chore(deps-dev): bump postcss from 8.5.10 to 8.5.12

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.10 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@8.5.10...8.5.12)

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

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

Author: dependabot[bot]

frontend/package.json

@@ -221,7 +221,7 @@
     "npm-run-all2": "^6.2.6",
     "oxfmt": "^0.42.0",
     "oxlint": "^1.58.0",
-    "postcss": "^8.5.6",
+    "postcss": "^8.5.12",
     "postcss-prefix-selector": "^2.1.1",
     "react": "^19.2.4",
     "react-compiler-runtime": "19.1.0-rc.3",