build(deps-dev): bump postcss from 8.4.5 to 8.4.31

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.5 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@8.4.5...8.4.31)

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

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -24,7 +24,7 @@
         "less": "^3.13.1",
         "less-loader": "^5.0.0",
         "livewire-vue": "^0.3.1",
-        "postcss": "^8.4.5",
+        "postcss": "^8.4.31",
         "prettier": "^2.5.1",
         "resolve-url-loader": "^3.1.2",
         "sass": "^1.15.2",