Bump uikit from 3.8.1 to 3.9.1

Bumps [uikit](https://github.com/uikit/uikit) from 3.8.1 to 3.9.1.
- [Release notes](https://github.com/uikit/uikit/releases)
- [Changelog](https://github.com/uikit/uikit/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/uikit/uikit/compare/v3.8.1...v3.9.1)

---
updated-dependencies:
- dependency-name: uikit
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

package.json

@@ -20,7 +20,7 @@
         "mux.js": "^5.14.1",
         "register-service-worker": "^1.7.1",
         "shaka-player": "3.2.1",
-        "uikit": "3.8.1",
+        "uikit": "3.9.1",
         "vue": "^3.2.21",
         "vue-i18n": "^9.2.0-beta.18",
         "vue-router": "^4.0.12",