deps(npm): bump happy-dom in /frontend/taskdeck-web

Bumps [happy-dom](https://github.com/capricorn86/happy-dom) from 15.11.7 to 20.8.9.
- [Release notes](https://github.com/capricorn86/happy-dom/releases)
- [Commits](capricorn86/happy-dom@v15.11.7...v20.8.9)

---
updated-dependencies:
- dependency-name: happy-dom
  dependency-version: 20.8.9
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

frontend/taskdeck-web/package-lock.json

@@ -54,7 +54,7 @@
     "baseline-browser-mapping": "^2.9.19",
     "eslint": "^8.57.1",
     "eslint-plugin-vue": "^9.33.0",
-    "happy-dom": "^15.11.7",
+    "happy-dom": "^20.8.9",
     "postcss": "^8.5.6",
     "tailwindcss": "^3.4.18",
     "typescript": "~5.9.3",