Bump happy-dom from 20.11.2 to 20.11.6 in /frontend

Bumps [happy-dom](https://github.com/capricorn86/happy-dom) from 20.11.2 to 20.11.6.
- [Release notes](https://github.com/capricorn86/happy-dom/releases)
- [Commits](capricorn86/happy-dom@v20.11.2...v20.11.6)

---
updated-dependencies:
- dependency-name: happy-dom
  dependency-version: 20.11.6
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

frontend/package-lock.json

@@ -24,7 +24,7 @@
     "eslint": "^10.8.0",
     "eslint-config-prettier": "^10.1.8",
     "globals": "^17.9.0",
-    "happy-dom": "^20.10.6",
+    "happy-dom": "^20.11.6",
     "lightningcss": "^1.30.2",
     "prettier": "^3.9.6",
     "puppeteer": "^25.5.0",