feat: add copy PNG buttons to charts - #3132

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: lunariajs/action@4911ad0736d1e3b20af4cb70f5079aea2327ed8e. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/