Bump postcss from 8.4.17 to 8.4.31 in /examples/radix-ui

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.17 to 8.4.31.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.17...8.4.31)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

examples/radix-ui/package.json

@@ -16,7 +16,7 @@
     "@types/node": "18.8.0",
     "@types/react": "18.0.21",
     "autoprefixer": "10.4.12",
-    "postcss": "8.4.17",
+    "postcss": "8.4.31",
     "tailwindcss": "3.1.8",
     "typescript": "4.8.4"
   }