Hue: Guard for when there is no brightness (#35151)

homeassistant/components/hue/light.py

@@ -259,6 +259,9 @@ class HueLight(LightEntity):
         else:
             bri = self.light.state.get("bri")
 
+        if bri is None:
+            return bri
+
         return hue_brightness_to_hass(bri)
 
     @property