SSLContext.sni_callback docs inaccurately describe available handshake info

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2021-03-21.14:53:57.553>
labels = ['expert-SSL', '3.8', '3.9', '3.10', 'type-feature', 'docs']
title = 'SSLContext.sni_callback docs inaccurately describe available handshake info'
updated_at = <Date 2022-03-14.06:38:02.964>
user = 'https://github.com/theandrew168'

bugs.python.org fields:

activity = <Date 2022-03-14.06:38:02.964>
actor = 'paulo-raca'
assignee = 'docs@python'
closed = False
closed_date = None
closer = None
components = ['Documentation', 'SSL']
creation = <Date 2021-03-21.14:53:57.553>
creator = 'theandrew168'
dependencies = []
files = []
hgrepos = []
issue_num = 43582
keywords = []
message_count = 9.0
messages = ['389231', '389236', '389239', '389250', '389254', '389260', '389261', '389506', '415120']
nosy_count = 8.0
nosy_names = ['janssen', 'christian.heimes', 'alex', 'njs', 'docs@python', 'dstufft', 'theandrew168', 'paulo-raca']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue43582'
versions = ['Python 3.8', 'Python 3.9', 'Python 3.10']