fix: Replace deprecated env vars

.env.example

@@ -24,7 +24,7 @@ TRACECAT__PUBLIC_RUNNER_URL=https://your-ngrok-runner-url
 # --- RabbitMQ ---
 RABBITMQ_PASS=guest
 RABBITMQ_USER=guest
-RABBITMQ_URI=amqp://${RABBITMQ_DEFAULT_USER}:${RABBITMQ_DEFAULT_PASS}@host.docker.internal/
+RABBITMQ_URI=amqp://${RABBITMQ_USER}:${RABBITMQ_PASS}@host.docker.internal/
 
 # --- Postgres ---
 POSTGRES_USER=postgres