Remove 'available' property from dehumidifier config (#5021)

Removed 'available' property from device configuration.

custom_components/tuya_local/devices/ldh7700_dehumidifier.yaml

@@ -36,13 +36,6 @@ entities:
       - id: 1
         type: boolean
         name: switch
-      - id: 5
-        type: string
-        name: available
-        mapping:
-          - dps_val: Continuities
-            value: true
-          - value: false
       - id: 4
         type: string
         name: speed