Fix bug pushing frame in _PY_FRAME_KW

_PY_FRAME_KW pushes a pointer to the new frame onto the stack for
consumption by the next uop. When pushing the frame fails, we do
not want to push the result (NULL) to the stack because it is not
a valid stackref.

The pre-existing arrangement works fine in the default build because
PyStackRef_NULL and NULL are the same value. The error handling code
in the interpreter calls `PyStackRef_XCLOSE()` on the value, which is
a no-op. In the free-threaded build the values are not the same, so
the `PyStackRef_XCLOSE()` in the error handler will attempt to decref
a null pointer.

Python/bytecodes.c

@@ -4289,17 +4289,19 @@ dummy_func(
             assert(Py_TYPE(callable_o) == &PyFunction_Type);
             int code_flags = ((PyCodeObject*)PyFunction_GET_CODE(callable_o))->co_flags;
             PyObject *locals = code_flags & CO_OPTIMIZED ? NULL : Py_NewRef(PyFunction_GET_GLOBALS(callable_o));
-            new_frame = _PyEvalFramePushAndInit(
+            _PyInterpreterFrame *temp = _PyEvalFramePushAndInit(
                 tstate, callable[0], locals,
                 args, positional_args, kwnames_o, frame
             );
             PyStackRef_CLOSE(kwnames);
             // The frame has stolen all the arguments from the stack,
             // so there is no need to clean them up.
+            INPUTS_DEAD();
             SYNC_SP();
-            if (new_frame == NULL) {
+            if (temp == NULL) {
                 ERROR_NO_POP();
             }
+            new_frame = temp;
         }
 
         op(_CHECK_FUNCTION_VERSION_KW, (func_version/2, callable[1], self_or_null[1], unused[oparg], kwnames -- callable[1], self_or_null[1], unused[oparg], kwnames)) {