mypy

gh-142754: Ensure that Element & Attr instances have the ownerDocumen… #18569

Job	Run time
Run mypy on Tools/cases_generator	20s
Run mypy on Tools/peg_generator	19s
Run mypy on Lib/_pyrepl	21s
Run mypy on Lib/test/libregrtest	17s
Run mypy on Tools/build	17s
Run mypy on Tools/clinic	22s
Run mypy on Tools/jit	20s
Run mypy on Lib/tomllib	18s
	2m 34s

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