fix: remove self-hosted runner from public repo - #29

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: daun/playwright-report-summary@1229105480a2a4bdd91598d8a146fbab41343fce. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/