feat(grok): grok-build-cli 启动前预检非特权 userns(Ubuntu 24.04+ 上它必然失败,但没有任何提示) - #752

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/