ci(deploy): remove unused WebSocket cluster environment variables

Remove `APP_WEBSOCKET_CLUSTER_INSTANCE_ID` from the deployment workflow as it is no longer required for the current configuration.

.gitea/workflows/deploy.yml

@@ -122,11 +122,10 @@ jobs:
               -e APP_SENSITIVE_ENABLED=true \
               -e APP_REPORT_AUTO_HIDE_THRESHOLD=3 \
               -e APP_WEBSOCKET_MODE=standalone \
-	            -e APP_WEBSOCKET_CLUSTER_INSTANCE_ID= \
-	            -e APP_WEBSOCKET_CLUSTER_MSG_CHANNEL=ws:msg \
-	            -e APP_WEBSOCKET_CLUSTER_ONLINE_TTL=60 \
-	            -e APP_WEBSOCKET_CLUSTER_HEARTBEAT_INTERVAL=20 \
-	            -e "APP_SETUP_SECRET=${{ secrets.SETUP_SECRET }}" \
+              -e APP_WEBSOCKET_CLUSTER_MSG_CHANNEL=ws:msg \
+              -e APP_WEBSOCKET_CLUSTER_ONLINE_TTL=60 \
+              -e APP_WEBSOCKET_CLUSTER_HEARTBEAT_INTERVAL=20 \
+              -e "APP_SETUP_SECRET=${{ secrets.SETUP_SECRET }}" \
               ${IMAGE}
             
             echo "=== Waiting for startup ==="