mypy

gh-149879: Fix multiprocessing resource tracker tests on Cygwin (#150… #21567

Job	Run time
Run mypy on Lib/_pyrepl	18s
Run mypy on Tools/cases_generator	18s
Run mypy on Lib/test/libregrtest	20s
Run mypy on Lib/tomllib	16s
Run mypy on Tools/check-c-api-docs	16s
Run mypy on Tools/build	19s
Run mypy on Tools/jit	20s
Run mypy on Tools/peg_generator	20s
Run mypy on Tools/clinic	18s
	2m 45s

Provide feedback