`_py_abc` breaks pattern matching

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2021-10-15.12:59:43.754>
labels = ['type-bug', '3.10', '3.11']
title = "pure Python class that has been registered as a `collections.abc.Sequence` can't be recgnized by the match statement without the `_abc` module"
updated_at = <Date 2021-10-15.15:30:45.212>
user = 'https://github.com/GalaxySnail'

bugs.python.org fields:

activity = <Date 2021-10-15.15:30:45.212>
actor = 'rhettinger'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = []
creation = <Date 2021-10-15.12:59:43.754>
creator = 'GalaxySnail'
dependencies = []
files = []
hgrepos = []
issue_num = 45483
keywords = []
message_count = 1.0
messages = ['404011']
nosy_count = 2.0
nosy_names = ['rhettinger', 'GalaxySnail']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue45483'
versions = ['Python 3.10', 'Python 3.11']