Fix duplicate call to async_write_ha_state when adding elkm1 entities (#141890)

When an entity is added state is always written in
add_to_platform_finish:

7336178e03/homeassistant/helpers/entity.py (L1384)

We should not do it in async_added_to_hass as well

homeassistant/components/elkm1/entity.py

@@ -100,7 +100,11 @@ class ElkEntity(Entity):
         return {"index": self._element.index + 1}
 
     def _element_changed(self, element: Element, changeset: dict[str, Any]) -> None:
-        pass
+        """Handle changes to the element.
+
+        This method is called when the element changes. It should be
+        overridden by subclasses to handle the changes.
+        """
 
     @callback
     def _element_callback(self, element: Element, changeset: dict[str, Any]) -> None:
@@ -111,7 +115,7 @@ class ElkEntity(Entity):
     async def async_added_to_hass(self) -> None:
         """Register callback for ElkM1 changes and update entity state."""
         self._element.add_callback(self._element_callback)
-        self._element_callback(self._element, {})
+        self._element_changed(self._element, {})
 
     @property
     def device_info(self) -> DeviceInfo: