build(deps): bump next from 15.4.1 to 15.5.6

Bumps [next](https://github.com/vercel/next.js) from 15.4.1 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](vercel/next.js@v15.4.1...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] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -20,7 +20,7 @@
     "jotai": "^2.12.5",
     "lightningcss": "^1.25.1",
     "lucide-react": "^0.525.0",
-    "next": "15.4.1",
+    "next": "15.5.6",
     "next-themes": "^0.4.6",
     "prettier": "^3.6.2",
     "react": "^19.0.0",