Leos Loo Too: light needs to be optional

Light state is not always reported.

Issue #1840

custom_components/tuya_local/devices/leos_loo_too.yaml

@@ -47,6 +47,7 @@ secondary_entities:
       - id: 16
         name: switch
         type: boolean
+        optional: true
   - entity: number
     category: config
     name: Cleaning delay