build(deps-dev): bump postcss in /backup_ms/frontend

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.19 to 8.4.31.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.19...8.4.31)

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

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

backup_ms/frontend/package.json

@@ -29,7 +29,7 @@
  "eslint-plugin-jsx-a11y": "^6.6.1",
  "eslint-plugin-react": "^7.31.11",
  "eslint-plugin-react-hooks": "^4.6.0",
- "postcss": "^8.4.19",
+ "postcss": "^8.4.31",
  "tailwindcss": "^3.2.4",
  "typescript": "^4.9.3",
  "vite": "^3.2.3"