Update nextjs monorepo

Author: renovate[bot]

package.json

@@ -17,7 +17,7 @@
     "date-fns": "^2.29.3",
     "gray-matter": "^4.0.3",
     "lodash": "^4.17.21",
-    "next": "12.1.0",
+    "next": "12.3.4",
     "nextjs-color-mode": "^1.0.5",
     "polished": "^4.1.3",
     "prism-react-renderer": "^1.3.5",