Replace PyObject_CallFunctionObjArgs() with fastcall

* PyObject_CallFunctionObjArgs(func, NULL) => _PyObject_CallNoArg(func)
* PyObject_CallFunctionObjArgs(func, arg, NULL) => _PyObject_CallArg1(func, arg)

PyObject_CallFunctionObjArgs() allocates 40 bytes on the C stack and requires
extra work to "parse" C arguments to build a C array of PyObject*.

_PyObject_CallNoArg() and _PyObject_CallArg1() are simpler and don't allocate
memory on the C stack.

This change is part of the fastcall project. The change on listsort() is
related to the issue #23507.
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 2a01f70..b74941a 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -2066,8 +2066,7 @@
             _Py_IDENTIFIER(__missing__);
             missing = _PyObject_LookupSpecial((PyObject *)mp, &PyId___missing__);
             if (missing != NULL) {
-                res = PyObject_CallFunctionObjArgs(missing,
-                                                   key, NULL);
+                res = _PyObject_CallArg1(missing, key);
                 Py_DECREF(missing);
                 return res;
             }