ci: harden GitHub Actions and Update Incubator Roadmap - #62

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: amannn/action-semantic-pull-request@e9fabac35e210fea40ca5b14c0da95a099eff26f. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/