Bump postcss from 8.4.21 to 8.4.31 in /website

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.21 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@8.4.21...8.4.31)

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

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

Author: dependabot[bot]

website/package.json

@@ -32,7 +32,7 @@
 		"eslint-plugin-prettier": "^5.0.0",
 		"open-props": "^1.5.3",
 		"open-props-scss": "^0.4.1",
-		"postcss": "^8.4.21",
+		"postcss": "^8.4.31",
 		"postcss-html": "^1.5.0",
 		"prettier": "^3.0.0",
 		"sass": "^1.57.1",