Bump postcss from 8.5.3 to 8.5.4 (#11075)

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.3 to 8.5.4.
- [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/8.5.3...8.5.4)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.4
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

package.json

@@ -117,7 +117,7 @@
     "netlify-cli": "^21.5.0",
     "npm-run-all": "^4.0.0",
     "osm-community-index": "~5.9.2",
-    "postcss": "^8.5.3",
+    "postcss": "^8.5.4",
     "postcss-prefix-selector": "^2.1.1",
     "serve-handler": "^6.1.6",
     "shelljs": "^0.10.0",