⬆️ Bump postcss from 8.4.45 to 8.4.47 in /web/app

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] <support@github.com>

web/app/package.json

@@ -39,7 +39,7 @@
     "eslint-plugin-react-hooks": "^4.6.2",
     "eslint-plugin-react-refresh": "^0.4.12",
     "globals": "^15.9.0",
-    "postcss": "^8.4.45",
+    "postcss": "^8.4.47",
     "tailwindcss": "^3.4.12",
     "typescript": "^5.6.2",
     "typescript-eslint": "^8.5.0",