fix (doel_tiplus_litterbox): make sand surface calibration optional

For compatibility with 65L version on issue #4117

custom_components/tuya_local/devices/doel_tiplus_litterbox.yaml

@@ -149,6 +149,7 @@ entities:
     dps:
       - id: 130
         type: integer
+        optional: true
         name: value
         range:
           min: 0