gh-140080: Clear `atexit` callbacks when memory allocation fails during finalization (GH-140103)

This fixes a regression introduced by GH-136004, in which finalization would hang while executing atexit handlers if the system was out of memory.

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Signed-off-by: yihong0618 <zouzou0208@gmail.com>
Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
Co-authored-by: Victor Stinner <vstinner@python.org>