build(deps): bump happy-dom in /examples/github-app (reactive#3835)

Bumps [happy-dom](https://github.com/capricorn86/happy-dom) from 20.8.8 to 20.8.9.
- [Release notes](https://github.com/capricorn86/happy-dom/releases)
- [Commits](capricorn86/happy-dom@v20.8.8...v20.8.9)

---
updated-dependencies:
- dependency-name: happy-dom
  dependency-version: 20.8.9
  dependency-type: indirect
...

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