chore(deps-dev): bump postcss from 8.4.14 to 8.5.10 in /frontend

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.14 to 8.5.10.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/8.4.14...8.5.10)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.10
  dependency-type: direct:development
...

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

frontend/apps/remark42/package.json

@@ -106,7 +106,7 @@
     "jest-localstorage-mock": "^2.4.21",
     "mini-css-extract-plugin": "^2.6.1",
     "npm-run-all": "^4.1.5",
-    "postcss": "^8.4.14",
+    "postcss": "^8.5.10",
     "postcss-html": "^1.4.1",
     "postcss-loader": "^7.0.0",
     "postcss-preset-env": "^7.7.2",