chore(deps-dev): bump postcss from 8.5.24 to 8.5.25

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.24 to 8.5.25.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/8.5.24...8.5.25)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.26
  dependency-type: indirect
...

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

sites/promo/package.json

@@ -35,7 +35,7 @@
     "@types/react-dom": "^19",
     "eslint": "^9",
     "eslint-config-next": "15.4.4",
-    "postcss": "^8.5.18",
+    "postcss": "^8.5.25",
     "prettier": "^3.6.2",
     "prettier-plugin-organize-imports": "^4.2.0",
     "prettier-plugin-tailwindcss": "^0.6.14",