Moes control panel: make backlight optional

Backlight dp is not coming through always.

Issue #2396

custom_components/tuya_local/devices/moes_controlpanel.yaml

@@ -39,6 +39,7 @@ secondary_entities:
     dps:
       - id: 36
         type: boolean
+        optional: true
         name: switch
   - entity: select
     name: Indicator