mypy

gh-143310: fix crash in Tcl object conversion with concurrent mutatio… #10017

Job	Run time
Run mypy on Tools/cases_generator	21s
Run mypy on Lib/tomllib	18s
Run mypy on Tools/check-c-api-docs	19s
Run mypy on Lib/test/libregrtest	18s
Run mypy on Lib/_pyrepl	19s
Run mypy on Tools/clinic	18s
Run mypy on Tools/peg_generator	18s
Run mypy on Tools/build	17s
Run mypy on Tools/jit	17s
	2m 45s

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