gdb: fix stop-replies for step, signalled vCont resume, and ctrl-c interrupt - #1654

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v3, actions/setup-python@v4, al-cheb/configure-pagefile-action@v1.2, microsoft/setup-msbuild@v1. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/