Add Fabric 26.1+ class templates (Mojmap) - #2639

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions-ecosystem/action-regex-match@d50fd2e7a37d0e617aea3d7ada663bd56862b9cc, actions/upload-artifact@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/