[Snyk] Security upgrade Umbraco.Cms from 13.12.1 to 14.0.0 - #123

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/upload-artifact@v5, gittools/actions/gitversion/execute@v3, gittools/actions/gitversion/setup@v3. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/