fix: ensure that shutdown works in loaderOnly mode (#6893)

packages/event-bus-redis/src/services/event-bus-redis.ts

@@ -62,7 +62,7 @@ export default class RedisEventBusService extends AbstractEventBusModuleService
 
   __hooks = {
     onApplicationShutdown: async () => {
-      await this.bullWorker_.close(true)
+      await this.bullWorker_?.close(true)
       await this.queue_.close()
       this.eventBusRedisConnection_.disconnect()
     },