Remove redudant state write in Smart Meter Texas (home-assistant#154126)

Author: srirams

homeassistant/components/smart_meter_texas/sensor.py

@@ -67,7 +67,7 @@ def extra_state_attributes(self):
         }
 
     @callback
-    def _state_update(self):
+    def _handle_coordinator_update(self) -> None:
         """Call when the coordinator has an update."""
         self._attr_available = self.coordinator.last_update_success
         if self._attr_available:
@@ -77,7 +77,6 @@ def _state_update(self):
     async def async_added_to_hass(self) -> None:
         """Subscribe to updates."""
         await super().async_added_to_hass()
-        self.async_on_remove(self.coordinator.async_add_listener(self._state_update))
 
         # If the background update finished before
         # we added the entity, there is no need to restore