build(deps-dev): bump postcss from 8.4.23 to 8.4.31

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.23 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@8.4.23...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 @@
     "jest": "29.5.0",
     "nunjucks": "3.2.4",
     "playwright": "1.34.1",
-    "postcss": "8.4.23",
+    "postcss": "8.4.31",
     "postcss-cli": "10.1.0",
     "terser": "5.17.6"
   },