mypy

gh-145376: Fix refleak and null pointer deref in unusual error path o… #10246

Job	Run time
Run mypy on Tools/cases_generator	20s
Run mypy on Tools/build	20s
Run mypy on Tools/clinic	19s
Run mypy on Lib/_pyrepl	18s
Run mypy on Lib/test/libregrtest	20s
Run mypy on Tools/peg_generator	19s
Run mypy on Tools/check-c-api-docs	19s
Run mypy on Tools/jit	17s
Run mypy on Lib/tomllib	22s
	2m 54s

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