Remove unnecessary should poll from cover classes (#41231)

homeassistant/components/garadget/cover.py

@@ -129,11 +129,6 @@ class GaradgetCover(CoverEntity):
         """Return the name of the cover."""
         return self._name
 
-    @property
-    def should_poll(self):
-        """No polling needed for a demo cover."""
-        return True
-
     @property
     def available(self):
         """Return True if entity is available."""