Bump less from 4.2.0 to 4.6.4 in /frontend

Bumps [less](https://github.com/less/less.js) from 4.2.0 to 4.6.4.
- [Release notes](https://github.com/less/less.js/releases)
- [Changelog](https://github.com/less/less.js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/less/less.js/commits)

---
updated-dependencies:
- dependency-name: less
  dependency-version: 4.6.4
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

frontend/package.json

@@ -45,7 +45,7 @@
     "@types/downloadjs": "^1.4.4",
     "eslint": "^9.24.0",
     "jsdom": "^25.0.1",
-    "less": "^4.2.0",
+    "less": "^4.6.4",
     "vite": "^5.4.10",
     "vitest": "^2.1.3"
   },