Bump postcss from 8.4.14 to 8.4.31

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.14 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@8.4.14...8.4.31)

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

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

package.json

@@ -34,7 +34,7 @@
         "autoprefixer": "^10.4.5",
         "hydefront": "^3.3.0",
         "laravel-mix": "^6.0.49",
-        "postcss": "^8.4.13",
+        "postcss": "^8.4.31",
         "prettier": "2.6.0",
         "tailwindcss": "^3.0.24"
     }