chore(deps-dev): bump postcss from 8.5.14 to 8.5.15 in /website (#461)

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.14 to 8.5.15.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.5.14...8.5.15)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.15
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

website/package-lock.json

@@ -28,7 +28,7 @@
     "@types/react-dom": "^19.2.3",
     "eslint": "^10.4.0",
     "eslint-config-next": "^16.2.7",
-    "postcss": "^8.5.12",
+    "postcss": "^8.5.15",
     "tailwindcss": "^4.3.0",
     "typescript": "^6.0.3"
   }