Bump postcss from 8.4.29 to 8.4.31

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.29 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@8.4.29...8.4.31)

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

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

Author: dependabot[bot]

package-lock.json

@@ -13,7 +13,7 @@
         "cssnano": "^6.0.1",
         "esbuild": "^0.17.0",
         "npm-run-all": "^4.1.5",
-        "postcss": "^8.4.27",
+        "postcss": "^8.4.31",
         "postcss-cli": "^10.1.0",
         "postcss-nesting": "^12.0.0"
     },