[3.11] gh-101266: Revert fix __sizeof__ for subclasses of int

[mdickinson]

This reverts commit cf89c16, which is causing reports of binary incompatibilities from Cython. See #101635

More details: Cython has logic that makes use of __basicsize__ and __itemsize__ to detect possible binary incompatibilities. The changes to bool.__basicsize__ and bool.__itemsize__ in #101579 cause Cython's checks to trigger for the bool type. Note that the bool layout hasn't actually changed, so there should be no actual binary incompatibility.

I believe we should be safe to leave the original fix in for the main branch.

• Issue: int and set subclass __sizeof__ under-reports the instance dictionary pointer #101266