chore(deps): bump next from 12.0.7 to 12.0.9 in /examples/next

Bumps [next](https://github.com/vercel/next.js) from 12.0.7 to 12.0.9.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v12.0.7...v12.0.9)

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

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

examples/next/package.json

@@ -17,7 +17,7 @@
     "@mdx-js/loader": "^1.6.22",
     "@mdx-js/react": "^1.6.22",
     "@next/mdx": "^12.0.7",
-    "next": "^12.0.7",
+    "next": "^12.0.9",
     "react": "^17.0.2",
     "react-dom": "^17.0.2",
     "theme-ui": "latest"