Bump @biomejs/biome from 2.2.5 to 2.2.6 in /frontend

Bumps [@biomejs/biome](https://github.com/biomejs/biome/tree/HEAD/packages/@biomejs/biome) from 2.2.5 to 2.2.6.
- [Release notes](https://github.com/biomejs/biome/releases)
- [Changelog](https://github.com/biomejs/biome/blob/main/packages/@biomejs/biome/CHANGELOG.md)
- [Commits](https://github.com/biomejs/biome/commits/@biomejs/biome@2.2.6/packages/@biomejs/biome)

---
updated-dependencies:
- dependency-name: "@biomejs/biome"
  dependency-version: 2.2.6
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

frontend/package.json

@@ -15,7 +15,7 @@
     "react-dom": "^19.1.1"
   },
   "devDependencies": {
-    "@biomejs/biome": "2.2.5",
+    "@biomejs/biome": "2.2.6",
     "@types/node": "^24.8.0",
     "@types/react": "^19.1.16",
     "@types/react-dom": "^19.1.9",