Fix for hvac_modes list being null (#25347)

* Fix for empty hvac_modes list

* Empty list instead of default value for hvac_modes

homeassistant/components/zwave/climate.py

@@ -244,7 +244,9 @@ class ZWaveClimate(ZWaveDeviceEntity, ClimateDevice):
 
         Need to be a subset of HVAC_MODES.
         """
-        return self._hvac_list
+        if self.values.mode:
+            return self._hvac_list
+        return []
 
     @property
     def hvac_action(self):