Backed out changeset b9c9691c72c5

Issue #28858: The change b9c9691c72c5 introduced a regression. It seems like
_PyObject_CallArg1() uses more stack memory than
PyObject_CallFunctionObjArgs().
diff --git a/Modules/_elementtree.c b/Modules/_elementtree.c
index bafcaa5..3837ff1 100644
--- a/Modules/_elementtree.c
+++ b/Modules/_elementtree.c
@@ -2457,7 +2457,7 @@
         PyObject *event = PyTuple_Pack(2, action, node);
         if (event == NULL)
             return -1;
-        res = _PyObject_CallArg1(self->events_append, event);
+        res = PyObject_CallFunctionObjArgs(self->events_append, event, NULL);
         Py_DECREF(event);
         if (res == NULL)
             return -1;