CI: run the CentOS 7 jobs' actions on a Node 24 built for glibc 2.17 - #277

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5, actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02, seanmiddleditch/gha-setup-ninja@8b297075da4cd2a5f1fd21fe011b499edf06e9d2. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/