[Nussu06]

cpython_native_callback stores Py_None in the argument tuple with PyTuple_SetItem, which steals a reference that was never taken, so each null argument (e.g. [std.native('f')(null) for i in std.range(1, N)]) drops one reference from None until CPython < 3.12 aborts with "Fatal Python error: none_dealloc: deallocating None"; take the reference first, with a regression test checking that sys.getrefcount(None) is unchanged after 100 null calls (fails with 100 references lost before the fix, passes after on 3.9 and 3.12).