mypy

GH-136410: Faster side exits #15822

Job	Run time
Run mypy on Lib/tomllib	17s
Run mypy on Lib/_pyrepl	17s
Run mypy on Tools/peg_generator	16s
Run mypy on Tools/build	19s
Run mypy on Tools/jit	22s
Run mypy on Tools/cases_generator	15s
Run mypy on Lib/test/libregrtest	17s
Run mypy on Tools/clinic	16s
	2m 19s

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