Update next-on-netlify to v2.3.0

v2.3.0 adds support for preview mode, among other things. Full changelog 
for next-on-netlify is available here: 
https://github.com/FinnWoelm/next-on-netlify/blob/master/CHANGELOG.md

Author: FinnWoelm

package-lock.json

@@ -7,7 +7,7 @@
   },
   "dependencies": {
     "next": "^9.4.4",
-    "next-on-netlify": "^2.0.0",
+    "next-on-netlify": "^2.3.0",
     "react": "^16.13.1",
     "react-dom": "^16.13.1"
   },