mypy

gh-151223: fix tsan data races in load global specializations (#151393) #21915

Job	Run time
Run mypy on Lib/tomllib	14s
Run mypy on Tools/build	15s
Run mypy on Tools/jit	15s
Run mypy on Tools/cases_generator	18s
Run mypy on Lib/test/libregrtest	22s
Run mypy on Tools/clinic	19s
Run mypy on Lib/_pyrepl	22s
Run mypy on Tools/check-c-api-docs	13s
Run mypy on Tools/peg_generator	13s
	2m 31s

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