mypy

gh-103847: fix cancellation safety of `asyncio.create_subprocess_exec… #17875

Job	Run time
Run mypy on Tools/clinic	16s
Run mypy on Tools/build	15s
Run mypy on Lib/test/libregrtest	21s
Run mypy on Lib/tomllib	16s
Run mypy on Lib/_pyrepl	23s
Run mypy on Tools/cases_generator	14s
Run mypy on Tools/peg_generator	21s
Run mypy on Tools/jit	17s
	2m 23s

Provide feedback