Update hub children on first update and delay subsequent updates (#1438)

kasa/smart/modules/devicemodule.py

@@ -19,12 +19,15 @@ class DeviceModule(SmartModule):
 
     def query(self) -> dict:
         """Query to execute during the update cycle."""
+        if self._device._is_hub_child:
+            # Child devices get their device info updated by the parent device.
+            return {}
         query = {
             "get_device_info": None,
         }
         # Device usage is not available on older firmware versions
         # or child devices of hubs
-        if self.supported_version >= 2 and not self._device._is_hub_child:
+        if self.supported_version >= 2:
             query["get_device_usage"] = None
 
         return query