build(deps-dev): bump happy-dom from 12.2.0 to 12.9.0 in /frontend

Bumps [happy-dom](https://github.com/capricorn86/happy-dom) from 12.2.0 to 12.9.0.
- [Release notes](https://github.com/capricorn86/happy-dom/releases)
- [Commits](https://github.com/capricorn86/happy-dom/compare/v12.2.0...v12.9.0)

---
updated-dependencies:
- dependency-name: happy-dom
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

frontend/package.json

@@ -60,7 +60,7 @@
     "eslint-plugin-import": "^2.28.1",
     "eslint-plugin-matrix-org": "^1.2.1",
     "eslint-plugin-prettier": "^5.0.0",
-    "happy-dom": "^12.2.0",
+    "happy-dom": "^12.9.0",
     "postcss": "^8.4.31",
     "prettier": "3.0.3",
     "react-test-renderer": "^18.2.0",