chore(deps): bump next from 15.2.4 to 15.4.8 in /references/d3-chat

Bumps [next](https://github.com/vercel/next.js) from 15.2.4 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@v15.2.4...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]

references/d3-chat/package.json

@@ -43,7 +43,7 @@
     "lucide-react": "^0.486.0",
     "marked": "^4.0.18",
     "nanoid": "^5.1.5",
-    "next": "15.2.4",
+    "next": "15.4.8",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
     "react-markdown": "^10.1.0",