mypy

gh-153298: Fix data race in `GenericAlias` parameter initialization o… #22393

Job	Run time
Run mypy on Lib/tomllib	28s
Run mypy on Tools/cases_generator	30s
Run mypy on Tools/check-c-api-docs	31s
Run mypy on Tools/clinic	30s
Run mypy on Tools/build	32s
Run mypy on Tools/jit	31s
Run mypy on Lib/_pyrepl	31s
Run mypy on Lib/test/libregrtest	33s
Run mypy on Tools/peg_generator	32s
	4m 38s

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