Bump laravel/slack-notification-channel from 2.5.0 to 3.2.0

Bumps [laravel/slack-notification-channel](https://github.com/laravel/slack-notification-channel) from 2.5.0 to 3.2.0.
- [Release notes](https://github.com/laravel/slack-notification-channel/releases)
- [Changelog](https://github.com/laravel/slack-notification-channel/blob/3.x/CHANGELOG.md)
- [Upgrade guide](https://github.com/laravel/slack-notification-channel/blob/3.x/UPGRADE.md)
- [Commits](laravel/slack-notification-channel@v2.5.0...v3.2.0)

---
updated-dependencies:
- dependency-name: laravel/slack-notification-channel
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

composer.json

@@ -20,7 +20,7 @@
         "laravel/framework": "^10.0",
         "laravel/horizon": "^5.12",
         "laravel/sanctum": "^3.2",
-        "laravel/slack-notification-channel": "^2.5",
+        "laravel/slack-notification-channel": "^3.2",
         "laravel/socialite": "^5.6",
         "laravel/tinker": "^2.8",
         "laravel/ui": "^4.2",