mypy

gh-145980: Fix copy/paste mistake in binascii.c (#146230) #20074

Job	Run time
Run mypy on Tools/clinic	18s
Run mypy on Tools/build	20s
Run mypy on Tools/jit	16s
Run mypy on Lib/tomllib	18s
Run mypy on Lib/_pyrepl	20s
Run mypy on Tools/cases_generator	18s
Run mypy on Tools/peg_generator	18s
Run mypy on Tools/check-c-api-docs	18s
Run mypy on Lib/test/libregrtest	21s
	2m 47s

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