Bump postcss from 8.4.27 to 8.4.28 (#1467)

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:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -52,7 +52,7 @@
     "passport-http-bearer": "^1.0.1",
     "passport-jwt": "^4.0.1",
     "passport-local": "^1.0.0",
-    "postcss": "^8.4.27",
+    "postcss": "^8.4.28",
     "rc": "1.2.8",
     "redux": "4.2.1",
     "request-promise": "^4.2.6",