mypin video feeder: use correct category for sensor

Issue #2781

custom_components/tuya_local/devices/mypin_6l_videopetfeeder.yaml

@@ -133,7 +133,7 @@ entities:
   - entity: sensor
     name: Food weight
     class: weight
-    category: config
+    category: diagnostic
     dps:
       - id: 232
         type: integer