Add device_class to Shelly cover domain (#46894)

Fix author

homeassistant/components/shelly/cover.py

@@ -3,6 +3,7 @@ from aioshelly import Block
 
 from homeassistant.components.cover import (
     ATTR_POSITION,
+    DEVICE_CLASS_SHUTTER,
     SUPPORT_CLOSE,
     SUPPORT_OPEN,
     SUPPORT_SET_POSITION,
@@ -75,6 +76,11 @@ class ShellyCover(ShellyBlockEntity, CoverEntity):
         """Flag supported features."""
         return self._supported_features
 
+    @property
+    def device_class(self) -> str:
+        """Return the class of the device."""
+        return DEVICE_CLASS_SHUTTER
+
     async def async_close_cover(self, **kwargs):
         """Close cover."""
         self.control_result = await self.block.set_state(go="close")