Mark Yamaha media player as unavailable when unresponsive (#85018)

homeassistant/components/yamaha/media_player.py

@@ -217,8 +217,10 @@ class YamahaDevice(MediaPlayerEntity):
             self._play_status = self.receiver.play_status()
         except requests.exceptions.ConnectionError:
             _LOGGER.info("Receiver is offline: %s", self._name)
+            self._attr_available = False
             return
 
+        self._attr_available = True
         if self.receiver.on:
             if self._play_status is None:
                 self._attr_state = MediaPlayerState.ON