Handle LinkPlay devices with no mac (#136272)

Co-authored-by: J. Nick Koston <[email protected]>

homeassistant/components/linkplay/entity.py

@@ -44,9 +44,15 @@ def __init__(self, bridge: LinkPlayBridge) -> None:
         if model != MANUFACTURER_GENERIC:
             model_id = bridge.device.properties["project"]
 
+        connections: set[tuple[str, str]] = set()
+        if "MAC" in bridge.device.properties:
+            connections.add(
+                (dr.CONNECTION_NETWORK_MAC, bridge.device.properties["MAC"])
+            )
+
         self._attr_device_info = dr.DeviceInfo(
             configuration_url=bridge.endpoint,
-            connections={(dr.CONNECTION_NETWORK_MAC, bridge.device.properties["MAC"])},
+            connections=connections,
             hw_version=bridge.device.properties["hardware"],
             identifiers={(DOMAIN, bridge.device.uuid)},
             manufacturer=manufacturer,