feat(BACKEND-TENSTORRENT-KEEPQUANT): Q5_K/Q6_K/Q8_0 decode chains and the q4km vehicle gate (#2959) - #3028

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/