build(deps-dev): bump postcss from 8.2.9 to 8.4.31

Bumps [postcss](https://github.com/postcss/postcss) from 8.2.9 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@8.2.9...8.4.31)

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

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

package.json

@@ -103,7 +103,7 @@
     "npm-run-all": "4.1.5",
     "onchange": "4.1.0",
     "pacote": "9.5.12",
-    "postcss": "8.2.10",
+    "postcss": "8.4.31",
     "postcss-dir-pseudo-class": "^5.0.0",
     "postcss-logical": "^4.0.2",
     "postcss-safe-important": "1.2.0",