mypy

GH-126910: Revert "Make `_Py_get_machine_stack_pointer` return the st… #20349

Job	Run time
Run mypy on Tools/cases_generator	19s
Run mypy on Lib/tomllib	19s
Run mypy on Tools/check-c-api-docs	22s
Run mypy on Lib/test/libregrtest	18s
Run mypy on Tools/build	16s
Run mypy on Tools/peg_generator	19s
Run mypy on Tools/clinic	17s
Run mypy on Lib/_pyrepl	18s
Run mypy on Tools/jit	21s
	2m 49s

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