fix(deps): update nextra monorepo to v3

Author: renovate[bot]

package.json

@@ -17,8 +17,8 @@
     "@vercel/analytics": "^1.1.1",
     "lodash-es": "^4.17.21",
     "next": "14.2.14",
-    "nextra": "2.13.4",
-    "nextra-theme-docs": "2.13.4",
+    "nextra": "3.0.2",
+    "nextra-theme-docs": "3.0.2",
     "react": "^18.2.0",
     "react-dom": "^18.2.0"
   },