Bump postcss from 8.5.2 to 8.5.6

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.2 to 8.5.6.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.5.2...8.5.6)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.6
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package.json

@@ -51,7 +51,7 @@
         "eslint-plugin-react": "^7.33.2",
         "htmlnano": "2.0.3",
         "mocha": "^11.1.0",
-        "postcss": "^8.5.2",
+        "postcss": "^8.5.6",
         "prettier": "3.3.3",
         "puppeteer": "^23.6.0",
         "puppeteer-core": "^24.1.1",