[hardening] TT-7621 fix: stop the PBT blob-load dead-states and never-ending bootstrap poll - #547

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, volta-cli/action@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/