build(deps-dev): bump postcss from 8.4.45 to 8.4.47 in /apps/OpenSign

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.45 to 8.4.47.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.45...8.4.47)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

apps/OpenSign/package-lock.json

@@ -112,7 +112,7 @@
     "eslint-plugin-react": "^7.34.3",
     "lint-staged": "^15.2.10",
     "mini-css-extract-plugin": "^2.9.1",
-    "postcss": "^8.4.45",
+    "postcss": "^8.4.47",
     "prettier": "^3.3.3",
     "pretty-quick": "^4.0.0",
     "tailwindcss": "^3.4.10",