fix(deps): update nextra monorepo to v3

Author: renovate[bot]

package.json

@@ -24,8 +24,8 @@
     "@vercel/analytics": "^1.3.1",
     "@vercel/speed-insights": "^1.0.13",
     "next": "^14.2.15",
-    "nextra": "^2.13.4",
-    "nextra-theme-docs": "^2.13.4",
+    "nextra": "^3.0.15",
+    "nextra-theme-docs": "^3.0.15",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",
     "react-feather": "^2.0.10",