fix(agent): surface kimi provider.api_error so the task fails visibly (#5760) - #5785

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/setup-go@v5, azure/setup-helm@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/