chore(deps-dev): bump postcss from 8.4.17 to 8.4.31

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] <support@github.com>

package.json

@@ -95,7 +95,7 @@
     "node-sass": "^7.0.3",
     "nodemon": "^2.0.20",
     "npm-run-all": "^4.1.5",
-    "postcss": "^8.4.17",
+    "postcss": "^8.4.31",
     "prop-types": "^15.7.2",
     "react-test-renderer": "^16.13.1",
     "redux-mock-store": "^1.5.4",