fix: upgrade multer to 2.2.0, 3.0.0-alpha.2 (CVE-2026-5079) - #1725

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/github-script@v7. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/