Bump @next/mdx in the next group across 1 directory

Bumps the next group with 1 update in the / directory: [@next/mdx](https://github.com/vercel/next.js/tree/HEAD/packages/next-mdx).


Updates `@next/mdx` from 14.2.5 to 14.2.13
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](https://github.com/vercel/next.js/commits/v14.2.13/packages/next-mdx)

---
updated-dependencies:
- dependency-name: "@next/mdx"
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: next
...

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

package.json

@@ -13,7 +13,7 @@
   "dependencies": {
     "@mdx-js/loader": "^3.0.1",
     "@mdx-js/react": "^3.0.1",
-    "@next/mdx": "^14.2.5",
+    "@next/mdx": "^14.2.13",
     "@vercel/node": "^3.2.15",
     "next": "^14.2.13",
     "next-sitemap": "^4.2.3",