Fix lints

src/livekit/MediaDevicesContext.tsx

@@ -59,7 +59,7 @@ function useObservableState<T>(
     // observable state doesn't run in SSR
     if (typeof window === "undefined" || !observable) return;
     const subscription = observable.subscribe(setState);
-    return () => subscription.unsubscribe();
+    return (): void => subscription.unsubscribe();
   }, [observable]);
   return state;
 }

src/livekit/useECConnectionState.ts

@@ -192,7 +192,7 @@ export function useECConnectionState(
       livekitRoom.on(RoomEvent.ConnectionStateChanged, onConnStateChanged);
     }
 
-    return () => {
+    return (): void => {
       if (oldRoom)
         oldRoom.off(RoomEvent.ConnectionStateChanged, onConnStateChanged);
     };