Bump postcss from 8.4.27 to 8.4.28

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.27 to 8.4.28.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.27...8.4.28)

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

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

package.json

@@ -13,7 +13,7 @@
   },
   "devDependencies": {
     "autoprefixer": "^10.4.15",
-    "postcss": "^8.4.27",
+    "postcss": "^8.4.28",
     "postcss-cli": "^10.1.0"
   }
 }