build(deps): bump @reduxjs/toolkit from 2.5.1 to 2.8.2 in /frontend

Bumps [@reduxjs/toolkit](https://github.com/reduxjs/redux-toolkit) from 2.5.1 to 2.8.2.
- [Release notes](https://github.com/reduxjs/redux-toolkit/releases)
- [Commits](https://github.com/reduxjs/redux-toolkit/compare/v2.5.1...v2.8.2)

---
updated-dependencies:
- dependency-name: "@reduxjs/toolkit"
  dependency-version: 2.8.2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

frontend/package.json

@@ -19,7 +19,7 @@
     ]
   },
   "dependencies": {
-    "@reduxjs/toolkit": "^2.5.1",
+    "@reduxjs/toolkit": "^2.8.2",
     "chart.js": "^4.4.4",
     "clsx": "^2.1.1",
     "i18next": "^24.2.0",