build(deps-dev): bump postcss

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


Updates `postcss` from 8.5.1 to 8.5.2
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.5.1...8.5.2)

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

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

Author: dependabot[bot]

apps/OpenSign/package-lock.json

@@ -113,7 +113,7 @@
     "eslint-plugin-react": "^7.37.4",
     "lint-staged": "^15.4.3",
     "mini-css-extract-plugin": "^2.9.2",
-    "postcss": "^8.5.1",
+    "postcss": "^8.5.2",
     "prettier": "^3.5.0",
     "pretty-quick": "^4.0.0",
     "tailwindcss": "^3.4.17",