upcloud: Provide unique ID for server entities (#13181)

homeassistant/components/upcloud.py

@@ -116,6 +116,11 @@ class UpCloudServerEntity(Entity):
         self.uuid = uuid
         self.data = None
 
+    @property
+    def unique_id(self) -> str:
+        """Return unique ID for the entity."""
+        return self.uuid
+
     @property
     def name(self):
         """Return the name of the component."""