mypy

gh-140928: Add a constant pool to all executors; Contant propagate using the pool #17671

Job	Run time
Run mypy on Lib/test/libregrtest	20s
Run mypy on Tools/build	16s
Run mypy on Lib/_pyrepl	18s
Run mypy on Tools/cases_generator	22s
Run mypy on Tools/peg_generator	18s
Run mypy on Tools/jit	21s
Run mypy on Tools/clinic	19s
Run mypy on Lib/tomllib	17s
	2m 31s

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