mypy

gh-137090: Remove redundant statement in ``Doc/library/concurrent.int… #9414

Job	Run time
Run mypy on Lib/tomllib	18s
Run mypy on Tools/build	19s
Run mypy on Tools/cases_generator	16s
Run mypy on Lib/test/libregrtest	24s
Run mypy on Tools/peg_generator	21s
Run mypy on Lib/_pyrepl	19s
Run mypy on Tools/clinic	16s
Run mypy on Tools/jit	15s
	2m 28s

Provide feedback