fix (casdon_kg1_waterdispenser): set units on water heater

In screenshot on issue #4231, the water heater appears disabled with
no state info. This may be the cause of both complaints:
 - there is no control for the hot water temperature
 - there is an invalid valve entity that cannot be deleted - the user seems to have jumped to the conclusion from the release notes that this is caused by the translation change due to the word "force".

custom_components/tuya_local/devices/casdon_kg1_waterdispenser.yaml

@@ -118,6 +118,7 @@ entities:
       - id: 12
         type: integer
         name: temperature
+        unit: C
         range:
           min: 10
           max: 100