Reference leak in ctypes._build_result() when numretvals > 1 and v == NULL

[hyongtao-code]

Bug report

Bug description:

_ctypes._build_result() leaks a reference to the result tuple when numretvals > 1 and v = NULL during result construction.
https://github.com/python/cpython/blob/main/Modules/_ctypes/_ctypes.c#L4559-L4562

CPython versions tested on:

CPython main branch

Operating systems tested on:

Windows

Linked PRs

• gh-143145: Fix reference leak in ctypes _build_result() #143131