chore: Bump stylelint in /frontend in the npm-version-updates group

Bumps the npm-version-updates group in /frontend with 1 update: [stylelint](https://github.com/stylelint/stylelint).


Updates `stylelint` from 16.11.0 to 16.12.0
- [Release notes](https://github.com/stylelint/stylelint/releases)
- [Changelog](https://github.com/stylelint/stylelint/blob/main/CHANGELOG.md)
- [Commits](stylelint/stylelint@16.11.0...16.12.0)

---
updated-dependencies:
- dependency-name: stylelint
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: npm-version-updates
...

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

frontend/package.json

@@ -31,7 +31,7 @@
     "jest-serializer-vue-tjw": "^3.20.0",
     "jsdom": "^25.0.1",
     "postcss-html": "^1.7.0",
-    "stylelint": "^16.11.0",
+    "stylelint": "^16.12.0",
     "stylelint-config-recommended-vue": "^1.5.0",
     "stylelint-config-standard": "^36.0.1",
     "vite": "^5.4.11",