Some server class attributes are missing in socketserver docs

Documentation

While working with socketserver recently I noticed that the allow_reuse_port class attribute is not documented but the allow_reuse_address attribute is.

https://github.com/python/cpython/blob/f9a5a3a3ef34e63dc197156e9a5f57842859ca04/Lib/socketserver.py#L185-L198

In addition there's a couple of places we could clean up right now, for instance address_family is still grouped with the per-instance attributes rather than the class attributes, request_queue_size is only applicable to TCP, and there's another missing undocumented class attribute for specifying max packet size that is only applicable to UDP.

Linked PRs

• gh-128320

socketserver のドキュメントから始め、そのクラス属性の説明を Lib/socketserver.py の 185-198 行付近と比較します。allow_reuse_port をドキュメント化し、address_family を正しくグループ化し、request_queue_size が TCP に適用されることを明確にし、UDP 専用の最大パケットサイズ属性をドキュメント化できれば完了です。issue には gh-128320 がリンクされています。