docs: fix infinite scroll, update next.js, other fixes (#9441)

* update nextjs

* badge + scroll fixes

www/apps/book/app/globals.css

@@ -16,6 +16,14 @@
     @apply bg-medusa-bg-highlight;
   }
 
+  * {
+    scrollbar-color: var(--docs-border-base) var(--docs-bg-base);
+  }
+
+  aside * {
+    scrollbar-color: var(--docs-border-base) var(--docs-bg-subtle);
+  }
+
   body[data-modal="opened"] {
     @apply !overflow-hidden;
   }

www/apps/book/package.json

@@ -16,10 +16,10 @@
   "dependencies": {
     "@mdx-js/loader": "^3.0.0",
     "@mdx-js/react": "^3.0.0",
-    "@next/mdx": "^14.2.3",
+    "@next/mdx": "^14.2.14",
     "clsx": "^2.1.0",
     "docs-ui": "*",
-    "next": "14.2.3",
+    "next": "14.2.14",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "rehype-mdx-code-props": "^2.0.0",