chore: Update current_rooms to return empty list instead of None

Change return type of current_rooms property to avoid returning None.

Author: allenporter

roborock/devices/traits/v1/home.py

@@ -222,10 +222,10 @@ def current_map_data(self) -> CombinedMapInfo | None:
         return self._home_map_info.get(current_map_flag)
 
     @property
-    def current_rooms(self) -> list[NamedRoomMapping] | None:
+    def current_rooms(self) -> list[NamedRoomMapping]:
         """Returns the room names for the current map."""
         if self.current_map_data is None:
-            return None
+            return []
         return self.current_map_data.rooms
 
     @property