build(deps): bump next in /projects/react/08_conference_speakers

Bumps [next](https://github.com/vercel/next.js) from 14.2.20 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@v14.2.20...v14.2.21)

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

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

Author: dependabot[bot]

projects/react/08_conference_speakers/package-lock.json

@@ -13,7 +13,7 @@
   "license": "ISC",
   "dependencies": {
     "axios": "^1.7.9",
-    "next": "^14.2.20",
+    "next": "^14.2.21",
     "react": "^18.3.1",
     "react-bootstrap": "^2.10.6",
     "react-dom": "^18.3.1"