#723: No scrollbar when the minimap is on: quadraui's MinimapLayout.scrollbar is computed and discarded, and sync_scrollbar_positions doesn't know the strip exists - #726

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/