mypy

gh-134201: Expand explanation of Base85 encodings in base64 docs (#13… #14775

Job	Run time
Run mypy on Lib/_pyrepl	15s
Run mypy on Lib/test/libregrtest	15s
Run mypy on Lib/tomllib	16s
Run mypy on Tools/build	14s
Run mypy on Tools/cases_generator	14s
Run mypy on Tools/clinic	17s
Run mypy on Tools/jit	17s
Run mypy on Tools/peg_generator	18s
	2m 6s

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