Fix all Sphinx reference warnings in `Doc/library/{xml*,pyexpat}.rst`

Doc/library/xml.dom.rst:42: py:class reference target not found: DOMImplementation [ref.class]
Doc/library/xml.dom.rst:42: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.rst:85: py:class reference target not found: DOMImplementation [ref.class]
Doc/library/xml.dom.rst:94: py:class reference target not found: DOMImplementation [ref.class]
Doc/library/xml.dom.rst:94: 'envvar' reference target not found: PYTHON_DOM [ref.envvar]
Doc/library/xml.dom.rst:100: py:meth reference target not found: hasFeature [ref.meth]
Doc/library/xml.dom.rst:100: py:class reference target not found: DOMImplementation [ref.class]
Doc/library/xml.dom.rst:111: py:attr reference target not found: namespaceURI [ref.attr]
Doc/library/xml.dom.rst:135: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:135: py:attr reference target not found: nodeType [ref.attr]
Doc/library/xml.dom.rst:162: py:class reference target not found: DOMImplementation [ref.class]
Doc/library/xml.dom.rst:165: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:168: py:class reference target not found: NodeList [ref.class]
Doc/library/xml.dom.rst:171: py:class reference target not found: DocumentType [ref.class]
Doc/library/xml.dom.rst:175: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.rst:178: py:class reference target not found: Element [ref.class]
Doc/library/xml.dom.rst:181: py:class reference target not found: Attr [ref.class]
Doc/library/xml.dom.rst:184: py:class reference target not found: Comment [ref.class]
Doc/library/xml.dom.rst:190: py:class reference target not found: ProcessingInstruction [ref.class]
Doc/library/xml.dom.rst:202: py:class reference target not found: DOMImplementation [ref.class]
Doc/library/xml.dom.rst:202: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.rst:202: py:class reference target not found: DocumentType [ref.class]
Doc/library/xml.dom.rst:216: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.rst:216: py:class reference target not found: Element [ref.class]
Doc/library/xml.dom.rst:216: py:class reference target not found: DocumentType [ref.class]
Doc/library/xml.dom.rst:226: py:class reference target not found: DocumentType [ref.class]
Doc/library/xml.dom.rst:236: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:241: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:241: py:const reference target not found: ELEMENT_NODE [ref.const]
Doc/library/xml.dom.rst:241: py:const reference target not found: ATTRIBUTE_NODE [ref.const]
Doc/library/xml.dom.rst:241: py:const reference target not found: TEXT_NODE [ref.const]
Doc/library/xml.dom.rst:241: py:const reference target not found: CDATA_SECTION_NODE [ref.const]
Doc/library/xml.dom.rst:241: py:const reference target not found: ENTITY_NODE [ref.const]
Doc/library/xml.dom.rst:241: py:const reference target not found: PROCESSING_INSTRUCTION_NODE [ref.const]
Doc/library/xml.dom.rst:241: py:const reference target not found: COMMENT_NODE [ref.const]
Doc/library/xml.dom.rst:241: py:const reference target not found: DOCUMENT_NODE [ref.const]
Doc/library/xml.dom.rst:241: py:const reference target not found: DOCUMENT_TYPE_NODE [ref.const]
Doc/library/xml.dom.rst:241: py:const reference target not found: NOTATION_NODE [ref.const]
Doc/library/xml.dom.rst:251: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:251: py:class reference target not found: Element [ref.class]
Doc/library/xml.dom.rst:251: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.rst:251: py:class reference target not found: Attr [ref.class]
Doc/library/xml.dom.rst:260: py:class reference target not found: NamedNodeMap [ref.class]
Doc/library/xml.dom.rst:301: py:attr reference target not found: tagName [ref.attr]
Doc/library/xml.dom.rst:307: py:attr reference target not found: tagName [ref.attr]
Doc/library/xml.dom.rst:319: py:attr reference target not found: tagName [ref.attr]
Doc/library/xml.dom.rst:319: py:attr reference target not found: name [ref.attr]
Doc/library/xml.dom.rst:374: py:meth reference target not found: unlink [ref.meth]
Doc/library/xml.dom.rst:403: py:class reference target not found: NodeList [ref.class]
Doc/library/xml.dom.rst:403: py:class reference target not found: Element [ref.class]
Doc/library/xml.dom.rst:403: py:meth reference target not found: getElementsByTagName [ref.meth]
Doc/library/xml.dom.rst:403: py:meth reference target not found: getElementsByTagNameNS [ref.meth]
Doc/library/xml.dom.rst:403: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:424: py:class reference target not found: NodeList [ref.class]
Doc/library/xml.dom.rst:432: py:class reference target not found: NodeList [ref.class]
Doc/library/xml.dom.rst:442: py:class reference target not found: DocumentType [ref.class]
Doc/library/xml.dom.rst:442: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.rst:442: py:attr reference target not found: doctype [ref.attr]
Doc/library/xml.dom.rst:450: py:class reference target not found: DocumentType [ref.class]
Doc/library/xml.dom.rst:450: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:481: py:class reference target not found: NamedNodeMap [ref.class]
Doc/library/xml.dom.rst:490: py:class reference target not found: NamedNodeMap [ref.class]
Doc/library/xml.dom.rst:502: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.rst:502: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:514: py:meth reference target not found: insertBefore [ref.meth]
Doc/library/xml.dom.rst:514: py:meth reference target not found: appendChild [ref.meth]
Doc/library/xml.dom.rst:521: py:meth reference target not found: insertBefore [ref.meth]
Doc/library/xml.dom.rst:521: py:meth reference target not found: appendChild [ref.meth]
Doc/library/xml.dom.rst:550: py:meth reference target not found: setAttributeNode [ref.meth]
Doc/library/xml.dom.rst:550: py:class reference target not found: Element [ref.class]
Doc/library/xml.dom.rst:558: py:meth reference target not found: setAttributeNode [ref.meth]
Doc/library/xml.dom.rst:558: py:class reference target not found: Element [ref.class]
Doc/library/xml.dom.rst:582: py:class reference target not found: Element [ref.class]
Doc/library/xml.dom.rst:582: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:594: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.rst:599: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.rst:621: py:class reference target not found: Attr [ref.class]
Doc/library/xml.dom.rst:661: py:attr reference target not found: name [ref.attr]
Doc/library/xml.dom.rst:669: py:attr reference target not found: namespaceURI [ref.attr]
Doc/library/xml.dom.rst:669: py:attr reference target not found: localName [ref.attr]
Doc/library/xml.dom.rst:686: py:class reference target not found: Attr [ref.class]
Doc/library/xml.dom.rst:686: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:710: py:attr reference target not found: nodeValue [ref.attr]
Doc/library/xml.dom.rst:719: py:class reference target not found: NamedNodeMap [ref.class]
Doc/library/xml.dom.rst:719: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:729: py:attr reference target not found: value [ref.attr]
Doc/library/xml.dom.rst:733: py:class reference target not found: Element [ref.class]
Doc/library/xml.dom.rst:743: py:class reference target not found: Comment [ref.class]
Doc/library/xml.dom.rst:743: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:759: py:class reference target not found: CDATASection [ref.class]
Doc/library/xml.dom.rst:759: py:attr reference target not found: nodeType [ref.attr]
Doc/library/xml.dom.rst:765: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:775: py:class reference target not found: CDATASection [ref.class]
Doc/library/xml.dom.rst:787: py:class reference target not found: Node [ref.class]
Doc/library/xml.dom.rst:847: py:class reference target not found: Attr [ref.class]
Doc/library/xml.dom.rst:858: py:class reference target not found: Element [ref.class]
Doc/library/xml.dom.rst:884: py:meth reference target not found: NamedNodeMap.removeNamedItem [ref.meth]
Doc/library/xml.dom.rst:928: py:const reference target not found: DOMSTRING_SIZE_ERR [ref.const]
Doc/library/xml.dom.rst:930: py:const reference target not found: HIERARCHY_REQUEST_ERR [ref.const]
Doc/library/xml.dom.rst:932: py:const reference target not found: INDEX_SIZE_ERR [ref.const]
Doc/library/xml.dom.rst:934: py:const reference target not found: INUSE_ATTRIBUTE_ERR [ref.const]
Doc/library/xml.dom.rst:936: py:const reference target not found: INVALID_ACCESS_ERR [ref.const]
Doc/library/xml.dom.rst:938: py:const reference target not found: INVALID_CHARACTER_ERR [ref.const]
Doc/library/xml.dom.rst:940: py:const reference target not found: INVALID_MODIFICATION_ERR [ref.const]
Doc/library/xml.dom.rst:942: py:const reference target not found: INVALID_STATE_ERR [ref.const]
Doc/library/xml.dom.rst:944: py:const reference target not found: NAMESPACE_ERR [ref.const]
Doc/library/xml.dom.rst:946: py:const reference target not found: NOT_FOUND_ERR [ref.const]
Doc/library/xml.dom.rst:948: py:const reference target not found: NOT_SUPPORTED_ERR [ref.const]
Doc/library/xml.dom.rst:950: py:const reference target not found: NO_DATA_ALLOWED_ERR [ref.const]
Doc/library/xml.dom.rst:952: py:const reference target not found: NO_MODIFICATION_ALLOWED_ERR [ref.const]
Doc/library/xml.dom.rst:954: py:const reference target not found: SYNTAX_ERR [ref.const]
Doc/library/xml.dom.rst:956: py:const reference target not found: WRONG_DOCUMENT_ERR [ref.const]
Doc/library/xml.dom.rst:1005: py:attr reference target not found: someValue [ref.attr]
Doc/library/xml.dom.rst:1005: py:meth reference target not found: _get_someValue [ref.meth]
Doc/library/xml.dom.rst:1005: py:attr reference target not found: anotherValue [ref.attr]
Doc/library/xml.dom.rst:1005: py:meth reference target not found: _get_anotherValue [ref.meth]
Doc/library/xml.dom.rst:1005: py:meth reference target not found: _set_anotherValue [ref.meth]
Doc/library/xml.dom.rst:1026: py:meth reference target not found: getElementsByTagName [ref.meth]

Doc/library/xml.dom.minidom.rst:41: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.minidom.rst:53: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.minidom.rst:56: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.minidom.rst:66: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.minidom.rst:66: py:func reference target not found: getDOMImplementation [ref.func]
Doc/library/xml.dom.minidom.rst:81: py:attr reference target not found: documentElement [ref.attr]
Doc/library/xml.dom.minidom.rst:90: py:meth reference target not found: unlink [ref.meth]
Doc/library/xml.dom.minidom.rst:115: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.minidom.rst:133: py:meth reference target not found: write [ref.meth]
Doc/library/xml.dom.minidom.rst:140: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.minidom.rst:219: py:class reference target not found: Document [ref.class]
Doc/library/xml.dom.minidom.rst:228: py:meth reference target not found: _get_foo [ref.meth]
Doc/library/xml.dom.minidom.rst:228: py:meth reference target not found: _set_foo [ref.meth]
Doc/library/xml.dom.minidom.rst:248: py:class reference target not found: NodeList [ref.class]
Doc/library/xml.dom.minidom.rst:256: py:class reference target not found: DOMTimeStamp [ref.class]
Doc/library/xml.dom.minidom.rst:258: py:class reference target not found: EntityReference [ref.class]

Doc/library/xml.dom.pulldom.rst:53: py:data reference target not found: START_ELEMENT [ref.data]
Doc/library/xml.dom.pulldom.rst:54: py:data reference target not found: END_ELEMENT [ref.data]
Doc/library/xml.dom.pulldom.rst:55: py:data reference target not found: COMMENT [ref.data]
Doc/library/xml.dom.pulldom.rst:56: py:data reference target not found: START_DOCUMENT [ref.data]
Doc/library/xml.dom.pulldom.rst:57: py:data reference target not found: END_DOCUMENT [ref.data]
Doc/library/xml.dom.pulldom.rst:58: py:data reference target not found: CHARACTERS [ref.data]
Doc/library/xml.dom.pulldom.rst:59: py:data reference target not found: PROCESSING_INSTRUCTION [ref.data]
Doc/library/xml.dom.pulldom.rst:60: py:data reference target not found: IGNORABLE_WHITESPACE [ref.data]
Doc/library/xml.dom.pulldom.rst:62: py:class reference target not found: xml.dom.minidom.Document [ref.class]
Doc/library/xml.dom.pulldom.rst:62: py:class reference target not found: xml.dom.minidom.Element [ref.class]
Doc/library/xml.dom.pulldom.rst:62: py:class reference target not found: xml.dom.minidom.Text [ref.class]
Doc/library/xml.dom.pulldom.rst:119: py:class reference target not found: xml.dom.minidom.Document [ref.class]
Doc/library/xml.dom.pulldom.rst:119: py:data reference target not found: START_DOCUMENT [ref.data]
Doc/library/xml.dom.pulldom.rst:119: py:class reference target not found: xml.dom.minidom.Element [ref.class]
Doc/library/xml.dom.pulldom.rst:119: py:data reference target not found: START_ELEMENT [ref.data]
Doc/library/xml.dom.pulldom.rst:119: py:data reference target not found: END_ELEMENT [ref.data]
Doc/library/xml.dom.pulldom.rst:119: py:class reference target not found: xml.dom.minidom.Text [ref.class]
Doc/library/xml.dom.pulldom.rst:119: py:data reference target not found: CHARACTERS [ref.data]

Doc/library/xml.sax.rst:36: py:func reference target not found: create_parser [ref.func]
Doc/library/xml.sax.rst:77: py:class reference target not found: xml.sax.xmlreader.Attributes [ref.class]
Doc/library/xml.sax.rst:77: py:class reference target not found: xml.sax.xmlreader.AttributesNS [ref.class]

Doc/library/xml.sax.reader.rst:11: py:func reference target not found: create_parser [ref.func]
Doc/library/xml.sax.reader.rst:24: py:meth reference target not found: parse [ref.meth]
Doc/library/xml.sax.reader.rst:71: py:class reference target not found: Attributes [ref.class]
Doc/library/xml.sax.reader.rst:71: py:meth reference target not found: startElement [ref.meth]
Doc/library/xml.sax.reader.rst:82: py:meth reference target not found: startElementNS [ref.meth]
Doc/library/xml.sax.reader.rst:82: py:class reference target not found: AttributesNS [ref.class]
Doc/library/xml.sax.reader.rst:173: py:exc reference target not found: SAXNotRecognizedException [ref.exc]
Doc/library/xml.sax.reader.rst:180: py:exc reference target not found: SAXNotRecognizedException [ref.exc]
Doc/library/xml.sax.reader.rst:187: py:exc reference target not found: SAXNotRecognizedException [ref.exc]
Doc/library/xml.sax.reader.rst:194: py:exc reference target not found: SAXNotRecognizedException [ref.exc]
Doc/library/xml.sax.reader.rst:330: py:class reference target not found: Attributes [ref.class]
Doc/library/xml.sax.reader.rst:333: py:class reference target not found: Attributes [ref.class]
Doc/library/xml.sax.reader.rst:333: py:meth reference target not found: collections.abc.Mapping.copy [ref.meth]
Doc/library/xml.sax.reader.rst:333: py:meth reference target not found: collections.abc.Mapping.get [ref.meth]
Doc/library/xml.sax.reader.rst:333: py:meth reference target not found: collections.abc.Mapping.items [ref.meth]
Doc/library/xml.sax.reader.rst:333: py:meth reference target not found: collections.abc.Mapping.keys [ref.meth]
Doc/library/xml.sax.reader.rst:333: py:meth reference target not found: collections.abc.Mapping.values [ref.meth]
Doc/library/xml.sax.reader.rst:366: py:class reference target not found: AttributesNS [ref.class]
Doc/library/xml.sax.reader.rst:369: py:class reference target not found: Attributes [ref.class]
Doc/library/xml.sax.reader.rst:369: py:class reference target not found: AttributesNS [ref.class]

Doc/library/xmlrpc.client.rst:38: py:class reference target not found: SafeTransport [ref.class]
Doc/library/xmlrpc.client.rst:38: py:class reference target not found: Transport [ref.class]
Doc/library/xmlrpc.client.rst:129: py:exc reference target not found: Error [ref.exc]
Doc/library/xmlrpc.client.rst:145: py:class reference target not found: Server [ref.class]
Doc/library/xmlrpc.client.rst:183: py:attr reference target not found: ServerProxy.system [ref.attr]

Doc/library/xmlrpc.server.rst:29: py:meth reference target not found: server_bind [ref.meth]
Doc/library/xmlrpc.server.rst:29: py:meth reference target not found: server_activate [ref.meth]
Doc/library/xmlrpc.server.rst:97: py:meth reference target not found: _dispatch [ref.meth]
Doc/library/xmlrpc.server.rst:108: py:meth reference target not found: _dispatch [ref.meth]
Doc/library/xmlrpc.server.rst:192: py:meth reference target not found: register_function [ref.meth]
Doc/library/xmlrpc.server.rst:311: py:meth reference target not found: _dispatch [ref.meth]

Doc/library/pyexpat.rst:25: py:class reference target not found: xmlparser [ref.class]
Doc/library/pyexpat.rst:35: py:mod reference target not found: pyexpat [ref.mod]
Doc/library/pyexpat.rst:66: py:class reference target not found: xmlparser [ref.class]
Doc/library/pyexpat.rst:94: py:attr reference target not found: StartElementHandler [ref.attr]
Doc/library/pyexpat.rst:94: py:attr reference target not found: EndElementHandler [ref.attr]
Doc/library/pyexpat.rst:118: py:attr reference target not found: StartElementHandler [ref.attr]
Doc/library/pyexpat.rst:125: py:mod reference target not found: pyexpat [ref.mod]
Doc/library/pyexpat.rst:125: py:class reference target not found: xmlparser [ref.class]
Doc/library/pyexpat.rst:141: py:class reference target not found: xmlparser [ref.class]
Doc/library/pyexpat.rst:193: py:const reference target not found: XML_PARAM_ENTITY_PARSING_NEVER [ref.const]
Doc/library/pyexpat.rst:193: py:const reference target not found: XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE [ref.const]
Doc/library/pyexpat.rst:193: py:const reference target not found: XML_PARAM_ENTITY_PARSING_ALWAYS [ref.const]
Doc/library/pyexpat.rst:377: py:class reference target not found: xmlparser [ref.class]
Doc/library/pyexpat.rst:390: py:class reference target not found: xmlparser [ref.class]
Doc/library/pyexpat.rst:426: py:class reference target not found: xmlparser [ref.class]
Doc/library/pyexpat.rst:426: py:meth reference target not found: Parse [ref.meth]
Doc/library/pyexpat.rst:426: py:meth reference target not found: ParseFile [ref.meth]
Doc/library/pyexpat.rst:453: py:class reference target not found: xmlparser [ref.class]
Doc/library/pyexpat.rst:475: py:class reference target not found: xmlparser [ref.class]
Doc/library/pyexpat.rst:638: py:const reference target not found: XML_ERROR_NOT_STANDALONE [ref.const]
Doc/library/pyexpat.rst:650: py:class reference target not found: xmlparser [ref.class]
Doc/library/pyexpat.rst:663: py:const reference target not found: XML_ERROR_EXTERNAL_ENTITY_HANDLING [ref.const]
Doc/library/pyexpat.rst:842: py:exc reference target not found: ExpatError [ref.exc]
Doc/library/pyexpat.rst:974: py:attr reference target not found: NotStandaloneHandler [ref.attr]
Doc/library/pyexpat.rst:994: py:meth reference target not found: UseForeignDTD [ref.meth]