Bump laravel/framework in /testapps/laravel/example-app

Bumps [laravel/framework](https://github.com/laravel/framework) from 8.83.27 to 8.83.28.
- [Release notes](https://github.com/laravel/framework/releases)
- [Changelog](https://github.com/laravel/framework/blob/11.x/CHANGELOG.md)
- [Commits](laravel/framework@v8.83.27...v8.83.28)

---
updated-dependencies:
- dependency-name: laravel/framework
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>