chore(deps-dev): bump postcss from 8.3.11 to 8.4.20

Bumps [postcss](https://github.com/postcss/postcss) from 8.3.11 to 8.4.20.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.3.11...8.4.20)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

package-lock.json

@@ -53,7 +53,7 @@
     "husky": "^6.0.0",
     "jest": "^27.0.5",
     "lint-staged": "^10.5.4",
-    "postcss": "^8.3.5",
+    "postcss": "^8.4.20",
     "rimraf": "^3.0.2",
     "stylelint": "^13.13.1",
     "stylelint-config-prettier": "^8.0.2",