GH-140058: Clear key and value if PyTuple_New fails in dictiter_iternextitem

[sergey-miryanov]

Following code should decref key and value if PyTuple_New fails:

cpython/Objects/dictobject.c

Lines 5720 to 5726 in 6481539

	else {
	result = PyTuple_New(2);
	if (result == NULL)
	return NULL;
	PyTuple_SET_ITEM(result, 0, key);
	PyTuple_SET_ITEM(result, 1, value);
	}

• Issue: Possible memory leak on fail path in dictiter_iternextitem #140058

[sergey-miryanov]

I believe this should skip news.
Should be backported to 3.13 and 3.14.

[picnixz]

@eendebakpt Couldn't we actually use the PyTuple_FromArray API here? If so, I would suggest fixing the refleak as part of the change (I don't know if we gain something)