Bump next from 8.0.4 to 9.3.1

Bumps [next](https://github.com/zeit/next.js) from 8.0.4 to 9.3.1.
- [Release notes](https://github.com/zeit/next.js/releases)
- [Commits](vercel/next.js@v8.0.4...v9.3.1)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

docs/package.json

@@ -51,7 +51,7 @@
     "moment": "^2.24.0",
     "moment-hijri": "^2.1.2",
     "moment-jalaali": "^0.9.1",
-    "next": "8.0.4",
+    "next": "9.3.1",
     "next-cookies": "2.0.3",
     "next-images": "^1.3.0",
     "next-transpile-modules": "^2.0.0",