fix: nextra version

Author: kopy-kat

package.json

@@ -20,8 +20,8 @@
   "type": "module",
   "dependencies": {
     "next": "^14.2.14",
-    "nextra": "latest",
-    "nextra-theme-docs": "latest",
+    "nextra": "^2.13.4",
+    "nextra-theme-docs": "^2.13.4",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",
     "react-icons": "^4.12.0",