gh-92810: Reduce memory usage by ABCMeta.__subclasscheck__

[dolfinus]

• Issue: _abc._abc_subclasscheck has very poor performance and (I think) a memory leak #92810

Alternative implementation of #131914 which doesn't modify class attributes on every __subclasscheck__ call. Instead it checks in __new__ does current class have def __subclasses(cls) overriden, and if so, enables case for scls in cls.__subclasses__(), which is disabled by default.

[bedevere-app]

Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.

[bedevere-app]

Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.

[bedevere-app]

Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.

[bedevere-app]

Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.