chore(deps-dev): bump postcss from 8.5.6 to 8.5.8

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.6 to 8.5.8.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.5.6...8.5.8)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.8
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

dashboard/frontend/package.json

@@ -76,7 +76,7 @@
     "eslint-plugin-react-hooks": "7.0.1",
     "eslint-plugin-react-refresh": "^0.5.2",
     "globals": "^17.4.0",
-    "postcss": "^8.4.49",
+    "postcss": "^8.5.8",
     "prettier": "^3.8.1",
     "rollup-plugin-visualizer": "^7.0.1",
     "tailwindcss": "^3.4.19",