#731: GTK: 22 Relm4-era widget handles are permanently None — the second orphan pocket #672 could not see (and why #723's fix cannot run) - #744

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