mypy

gh-62825: Fix encoding aliases "KS_C_5601-1987", "KS X 1001", etc (GH… #21734

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

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