`_Py_RefcntAdd` doesn't respect immortality

[brandtbucher]

This is used by list and tuple internally:

>>> import sys
>>> sys.getrefcount(None) == (1 << 32) - 1
True
>>> refs = [None] * 42
>>> sys.getrefcount(None) == (1 << 32) - 1
False
>>> del refs
>>> sys.getrefcount(None) == (1 << 32) - 1
True

I'll have a PR up in a bit.

CC: @ericsnowcurrently, @eduardo-elizondo

Linked PRs

• GH-104142: Fix _Py_RefcntAdd to respect immortality #104143