Bump next from 13.4.19 to 13.5.1 in /docs

Bumps [next](https://github.com/vercel/next.js) from 13.4.19 to 13.5.1.
- [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/compare/v13.4.19...v13.5.1)

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

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

docs/package.json

@@ -8,7 +8,7 @@
   "dependencies": {
     "@vercel/analytics": "^1.0.2",
     "docsgpt": "^0.2.4",
-    "next": "^13.4.19",
+    "next": "^13.5.1",
     "nextra": "^2.12.3",
     "nextra-theme-docs": "^2.12.3",
     "react": "^18.2.0",