fix: update next to 16.1.6 to resolve Dependabot duplicate PR issue

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

apps/site/package.json

@@ -14,7 +14,7 @@
     "fumadocs-mdx": "14.2.6",
     "fumadocs-ui": "16.4.8",
     "lucide-react": "^0.563.0",
-    "next": "16.1.4",
+    "next": "16.1.6",
     "react": "^19.2.3",
     "react-dom": "^19.2.3",
     "tailwind-merge": "^3.4.0"