Bump next from 15.3.6 to 15.4.8 in /examples/nextjs

Bumps [next](https://github.com/vercel/next.js) from 15.3.6 to 15.4.8.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v15.3.6...v15.4.8)

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.4.8
  dependency-type: direct:production
...

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

Author: dependabot[bot]

examples/nextjs/package.json

@@ -12,7 +12,7 @@
     "@next/env": "^15.3.5",
     "jotai": "^2.12.5",
     "motion": "^12.23.3",
-    "next": "15.3.6",
+    "next": "15.4.8",
     "react": "^19.1.0",
     "react-dom": "^19.1.0",
     "solapi": "latest",