chore(deps): bump next from 14.2.15 to 14.2.21 in /typescript

Bumps [next](https://github.com/vercel/next.js) from 14.2.15 to 14.2.21.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v14.2.15...v14.2.21)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

typescript/create-onchain-agent/templates/next/package.json

@@ -20,7 +20,7 @@
     "@tanstack/react-query": "^5",
     "ai": "^4.1.54",
     "bs58": "^6.0.0",
-    "next": "14.2.15",
+    "next": "14.2.21",
     "react": "^18",
     "react-dom": "^18",
     "react-markdown": "^10.0.0",