mypy

gh-144133: Add a warning to the `encodings.punycode` documentation (#… #22010

Job	Run time
Run mypy on Tools/jit	19s
Run mypy on Tools/check-c-api-docs	21s
Run mypy on Lib/tomllib	16s
Run mypy on Tools/build	21s
Run mypy on Tools/peg_generator	19s
Run mypy on Lib/_pyrepl	22s
Run mypy on Tools/cases_generator	18s
Run mypy on Lib/test/libregrtest	21s
Run mypy on Tools/clinic	17s
	2m 54s

Provide feedback