mypy

Use the latest dev container image perpetually (#137734) #16156

Job	Run time
Run mypy on Lib/_pyrepl	20s
Run mypy on Tools/cases_generator	18s
Run mypy on Lib/test/libregrtest	18s
Run mypy on Tools/clinic	17s
Run mypy on Tools/jit	22s
Run mypy on Tools/build	15s
Run mypy on Tools/peg_generator	20s
Run mypy on Lib/tomllib	16s
	2m 26s

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