mypy

gh-71450: Document that Tcl sets the HOME variable on Windows (GH-152… #22188

Job	Run time
Run mypy on Tools/build	19s
Run mypy on Lib/_pyrepl	20s
Run mypy on Tools/jit	18s
Run mypy on Tools/clinic	19s
Run mypy on Tools/peg_generator	21s
Run mypy on Lib/test/libregrtest	19s
Run mypy on Tools/cases_generator	18s
Run mypy on Tools/check-c-api-docs	17s
Run mypy on Lib/tomllib	18s
	2m 49s

Provide feedback