mypy

Docs: Prepare for Sphinx 9 (#142057) #18191

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

Provide feedback