mypy

gh-132657: add regression test for `PySet_Contains` with unhashable t… #17891

Job	Run time
Run mypy on Lib/test/libregrtest	16s
Run mypy on Tools/jit	18s
Run mypy on Tools/build	18s
Run mypy on Tools/cases_generator	17s
Run mypy on Lib/tomllib	20s
Run mypy on Lib/_pyrepl	28s
Run mypy on Tools/peg_generator	18s
Run mypy on Tools/clinic	23s
	2m 38s

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