mypy

gh-127949: remove asyncio policy system #21847

Job	Run time
Run mypy on Tools/clinic	19s
Run mypy on Tools/jit	23s
Run mypy on Tools/build	19s
Run mypy on Lib/_pyrepl	19s
Run mypy on Lib/tomllib	21s
Run mypy on Tools/cases_generator	19s
Run mypy on Tools/peg_generator	20s
Run mypy on Lib/test/libregrtest	23s
Run mypy on Tools/check-c-api-docs	18s
	3m 1s

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