build(deps-dev): bump happy-dom from 14.12.3 to 15.7.0 in /frontend

Bumps [happy-dom](https://github.com/capricorn86/happy-dom) from 14.12.3 to 15.7.0.
- [Release notes](https://github.com/capricorn86/happy-dom/releases)
- [Commits](capricorn86/happy-dom@v14.12.3...v15.7.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

frontend/package-lock.json

@@ -73,7 +73,7 @@
     "eslint-import-resolver-typescript": "^3.6.1",
     "eslint-plugin-import": "^2.29.1",
     "eslint-plugin-matrix-org": "^1.2.1",
-    "happy-dom": "^14.12.3",
+    "happy-dom": "^15.7.0",
     "i18next-parser": "^9.0.2",
     "postcss": "^8.4.41",
     "postcss-modules": "^6.0.0",