Bump next from 15.4.5 to 15.4.8

Bumps [next](https://github.com/vercel/next.js) from 15.4.5 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@v15.4.5...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

@@ -14,7 +14,7 @@
   "dependencies": {
     "@m2d/react-markdown": "workspace:*",
     "@repo/shared": "workspace:*",
-    "next": "^15.4.5",
+    "next": "^15.4.8",
     "nextjs-darkmode-lite": "^1.0.10",
     "nextjs-themes": "^4.0.6",
     "react": "^19.1.1",