chore(deps): bump github.com/go-jose/go-jose/v4 from 4.1.4 to 4.1.6 in /backend - #4459

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, dorny/paths-filter@v3. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/