Bump dompurify from 3.2.6 to 3.4.0 in /ui

Bumps [dompurify](https://github.com/cure53/DOMPurify) from 3.2.6 to 3.4.0.
- [Release notes](https://github.com/cure53/DOMPurify/releases)
- [Commits](https://github.com/cure53/DOMPurify/compare/3.2.6...3.4.0)

---
updated-dependencies:
- dependency-name: dompurify
  dependency-version: 3.4.0
  dependency-type: direct:production
...

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

ui/package.json

@@ -49,7 +49,7 @@
     "chartjs-adapter-moment": "^1.0.0",
     "core-js": "^3.21.1",
     "cronstrue": "^2.26.0",
-    "dompurify": "^3.2.6",
+    "dompurify": "^3.4.0",
     "enquire.js": "^2.1.6",
     "js-cookie": "^2.2.1",
     "lodash": "^4.17.15",