chore(deps-dev): bump @tailwindcss/postcss from 4.1.18 to 4.2.4

Bumps [@tailwindcss/postcss](https://github.com/tailwindlabs/tailwindcss/tree/HEAD/packages/@tailwindcss-postcss) from 4.1.18 to 4.2.4.
- [Release notes](https://github.com/tailwindlabs/tailwindcss/releases)
- [Changelog](https://github.com/tailwindlabs/tailwindcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/tailwindlabs/tailwindcss/commits/v4.2.4/packages/@tailwindcss-postcss)

---
updated-dependencies:
- dependency-name: "@tailwindcss/postcss"
  dependency-version: 4.2.4
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

examples/slack-kit-example/package.json

@@ -19,7 +19,7 @@
     "react-dom": "^19.2.5"
   },
   "devDependencies": {
-    "@tailwindcss/postcss": "^4.1.18",
+    "@tailwindcss/postcss": "^4.2.4",
     "@types/node": "^24",
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.1.6",