Bump next from 14.2.14 to 14.2.21

Bumps [next](https://github.com/vercel/next.js) from 14.2.14 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@v14.2.14...v14.2.21)

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

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

Author: dependabot[bot]

apps/nextra/package.json

@@ -41,7 +41,7 @@
     "graphql-ws": "^5.16.0",
     "intersection-observer": "^0.10.0",
     "markdown-to-jsx": "^6.11.4",
-    "next": "^14.2.10",
+    "next": "^14.2.21",
     "next-sitemap": "^4.2.3",
     "nextra": "3.0.7",
     "nextra-theme-docs": "3.0.7",