Fix linting issues (#12898)

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

stdlib/warnings.pyi

@@ -1,5 +1,5 @@
-import sys
 import re
+import sys
 from _warnings import warn as warn, warn_explicit as warn_explicit
 from collections.abc import Sequence
 from types import ModuleType, TracebackType