mypy

gh-143636: fix a crash when calling `replace` on invalid `Simpl… #10279

Job	Run time
Run mypy on Lib/test/libregrtest	19s
Run mypy on Tools/check-c-api-docs	15s
Run mypy on Tools/build	17s
Run mypy on Tools/clinic	18s
Run mypy on Lib/_pyrepl	17s
Run mypy on Tools/jit	18s
Run mypy on Tools/cases_generator	20s
Run mypy on Tools/peg_generator	18s
Run mypy on Lib/tomllib	18s
	2m 40s

Provide feedback