(fix) test case should through error only in range[400,500)

app/test_main.py

@@ -66,4 +66,6 @@ async def test_forward_notification_failure():
             transport=ASGITransport(app=app), base_url="http://test"
         ) as ac:
             response = await ac.post("/notification", json=req)
-            assert not response.status_code == 204, description
+            assert response.status_code >= 400 and response.status_code < 500, (
+                description
+            )