fix: upgrade postcss from 8.4.31 to 8.4.40

Snyk has created this PR to upgrade postcss from 8.4.31 to 8.4.40.

See this package in npm:
postcss

See this project in Snyk:
https://app.snyk.io/org/nexuscompute/project/cdfc5801-a026-478e-bb78-4d73ccaeec7f?utm_source=github&utm_medium=referral&page=upgrade-pr

examples/cms-contentful/package.json

@@ -17,7 +17,7 @@
     "contentful-import": "^9.0.4",
     "date-fns": "2.30.0",
     "next": "latest",
-    "postcss": "8.4.31",
+    "postcss": "8.4.40",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "tailwindcss": "^3.3.3",