Bump happy-dom from 18.0.1 to 20.0.4 in /cloudproxy-ui

Bumps [happy-dom](https://github.com/capricorn86/happy-dom) from 18.0.1 to 20.0.4.
- [Release notes](https://github.com/capricorn86/happy-dom/releases)
- [Commits](capricorn86/happy-dom@v18.0.1...v20.0.4)

---
updated-dependencies:
- dependency-name: happy-dom
  dependency-version: 20.0.4
  dependency-type: direct:development
...

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

Author: dependabot[bot]

cloudproxy-ui/package-lock.json

@@ -39,7 +39,7 @@
     "cypress": "^14.5.4",
     "eslint": "^8.57.0",
     "eslint-plugin-vue": "^9.22.0",
-    "happy-dom": "^18.0.1",
+    "happy-dom": "^20.0.4",
     "msw": "^2.10.5",
     "vitest": "^3.2.4",
     "wait-on": "^8.0.4"