chore(deps-dev): bump postcss

Bumps the npm_and_yarn group with 1 update in the /frontend directory: [postcss](https://github.com/postcss/postcss).


Updates `postcss` from 8.5.8 to 8.5.12
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.5.8...8.5.12)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.12
  dependency-type: direct:development
  dependency-group: npm_and_yarn
...

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

Author: dependabot[bot]

frontend/package-lock.json

@@ -71,7 +71,7 @@
     "eslint-plugin-unused-imports": "^4.1.4",
     "husky": "^9.1.7",
     "lint-staged": "^16.4.0",
-    "postcss": "^8.4.49",
+    "postcss": "^8.5.12",
     "prettier": "^3.5.3",
     "prettier-plugin-tailwindcss": "^0.7.2",
     "tailwindcss": "^4.2.2",