build(deps): bump next from 15.3.4 to 15.5.6

Bumps [next](https://github.com/vercel/next.js) from 15.3.4 to 15.5.6.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](https://github.com/vercel/next.js/compare/v15.3.4...v15.5.6)

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.5.6
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

package.json

@@ -74,7 +74,7 @@
     "leaflet": "^1.9.4",
     "lucide-react": "^0.525.0",
     "motion": "^12.19.2",
-    "next": "^15.3.4",
+    "next": "^15.5.6",
     "next-auth": "^4.24.11",
     "next-themes": "^0.4.6",
     "node-cron": "^4.1.1",