build(deps-dev): bump postcss from 8.4.48 to 8.4.49 in /frontend

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.48 to 8.4.49.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.48...8.4.49)

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

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

frontend/package.json

@@ -70,7 +70,7 @@
     "jest-fetch-mock": "3.0.3",
     "node-mocks-http": "1.16.1",
     "pino-pretty": "11.3.0",
-    "postcss": "8.4.48",
+    "postcss": "8.4.49",
     "prettier": "3.3.3",
     "prettier-plugin-tailwindcss": "0.6.8",
     "react-test-renderer": "18.3.1",