gh-145688: Use identity check instead of name+module allowlist

Per @AlexWaygood's review, checking base.__module__ in {'typing',
'typing_extensions'} is fragile and would break third-party libraries
like beartype that define their own Protocol using _ProtocolMeta.

Use `base is Protocol or base is Generic` instead, which is the same
pattern already used at line 1176 in _generic_class_getitem. This
precisely targets the two base classes we want to skip without
affecting any third-party Protocol implementations.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: mvanhorn

Lib/typing.py

@@ -1884,7 +1884,7 @@ def _get_protocol_attrs(cls):
     """
     attrs = set()
     for base in cls.__mro__[:-1]:  # without object
-        if base.__name__ in {'Protocol', 'Generic'} and base.__module__ in {'typing', 'typing_extensions'}:
+        if base is Protocol or base is Generic:
             continue
         try:
             annotations = base.__annotations__