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](https://github.com/postcss/postcss/compare/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

@@ -55,7 +55,7 @@
     "lato-font": "^3.0.0",
     "mini-css-extract-plugin": "^2.7.6",
     "node-sass": "^9.0.0",
-    "postcss": "^8.4.27",
+    "postcss": "^8.4.28",
     "postcss-loader": "^7.3.3",
     "postcss-scss": "^4.0.6",
     "sass": "^1.65.1",