fix: upgrade @types/mdx from 2.0.3 to 2.0.8

Snyk has created this PR to upgrade @types/mdx from 2.0.3 to 2.0.8.

See this package in npm:
https://www.npmjs.com/package/@types/mdx

See this project in Snyk:
https://app.snyk.io/org/sammytezzy/project/0b5526cd-23ab-4885-bc8e-6a6e935a112f?utm_source=github&utm_medium=referral&page=upgrade-pr

examples/app-dir-mdx/package.json

@@ -7,7 +7,7 @@
   },
   "dependencies": {
     "@next/mdx": "latest",
-    "@types/mdx": "2.0.3",
+    "@types/mdx": "2.0.8",
     "@types/node": "18.11.18",
     "@types/react": "18.0.27",
     "@types/react-dom": "18.0.10",