mypy

gh-86519: Update docs for `prefixmatch` (#148096) #20718

Job	Run time
Run mypy on Tools/cases_generator	18s
Run mypy on Tools/build	20s
Run mypy on Lib/_pyrepl	20s
Run mypy on Tools/check-c-api-docs	20s
Run mypy on Lib/tomllib	18s
Run mypy on Lib/test/libregrtest	20s
Run mypy on Tools/jit	22s
Run mypy on Tools/clinic	15s
Run mypy on Tools/peg_generator	22s
	2m 55s

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