Import from collections.abc wherever possible (#7635)

stdlib/warnings.pyi

@@ -1,6 +1,7 @@
 from _warnings import warn as warn, warn_explicit as warn_explicit
+from collections.abc import Sequence
 from types import ModuleType, TracebackType
-from typing import Any, Sequence, TextIO, overload
+from typing import Any, TextIO, overload
 from typing_extensions import Literal, TypeAlias
 
 __all__ = [