Update typing_extensions imports in stdlib (#11244)

Co-authored-by: AlexWaygood <alex.waygood@gmail.com>

stdlib/dbm/__init__.pyi

@@ -1,6 +1,7 @@
 from collections.abc import Iterator, MutableMapping
 from types import TracebackType
-from typing_extensions import Literal, Self, TypeAlias
+from typing import Literal
+from typing_extensions import Self, TypeAlias
 
 __all__ = ["open", "whichdb", "error"]