Remove some pytype workarounds from stdlib (#14470)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

stdlib/unittest/case.pyi

@@ -2,18 +2,16 @@ import logging
 import sys
 import unittest.result
 from _typeshed import SupportsDunderGE, SupportsDunderGT, SupportsDunderLE, SupportsDunderLT, SupportsRSub, SupportsSub
+from builtins import _ClassInfo
 from collections.abc import Callable, Container, Iterable, Mapping, Sequence, Set as AbstractSet
 from contextlib import AbstractContextManager
 from re import Pattern
 from types import GenericAlias, TracebackType
 from typing import Any, AnyStr, Final, Generic, NoReturn, Protocol, SupportsAbs, SupportsRound, TypeVar, overload
-from typing_extensions import Never, ParamSpec, Self, TypeAlias
+from typing_extensions import Never, ParamSpec, Self
 from unittest._log import _AssertLogsContext, _LoggingWatcher
 from warnings import WarningMessage
 
-if sys.version_info >= (3, 10):
-    from types import UnionType
-
 _T = TypeVar("_T")
 _S = TypeVar("_S", bound=SupportsSub[Any, Any])
 _E = TypeVar("_E", bound=BaseException)
@@ -60,14 +58,6 @@ class SkipTest(Exception):
 
 class _SupportsAbsAndDunderGE(SupportsDunderGE[Any], SupportsAbs[Any], Protocol): ...
 
-# Keep this alias in sync with builtins._ClassInfo
-# We can't import it from builtins or pytype crashes,
-# due to the fact that pytype uses a custom builtins stub rather than typeshed's builtins stub
-if sys.version_info >= (3, 10):
-    _ClassInfo: TypeAlias = type | UnionType | tuple[_ClassInfo, ...]
-else:
-    _ClassInfo: TypeAlias = type | tuple[_ClassInfo, ...]
-
 class TestCase:
     failureException: type[BaseException]
     longMessage: bool