test: Update WORKFLOW_SERVER_URL_OVERRIDE to https://workflow-server-ako6y9lzo.vercel.sh

Author: vercel-gh-bot-3[bot]

packages/world-vercel/src/utils.ts

@@ -32,7 +32,7 @@ import { version } from './version.js';
  * `main` — rewritten by external CI for branch-deployment testing.
  * Prefer `VERCEL_WORKFLOW_SERVER_URL` for deployment-time configuration.
  */
-export const WORKFLOW_SERVER_URL_OVERRIDE = '';
+export const WORKFLOW_SERVER_URL_OVERRIDE = 'https://workflow-server-ako6y9lzo.vercel.sh';
 
 /**
  * HTTP methods that are safe to transparently re-issue inside the adapter.