Add Laravel 11 support

[pxpm]

This PR add Laravel 11 support to Backpack.

In order to support Laravel 10 and Laravel 11 we needed to do some modifications mainly in our DatabaseSchema to accomodate the fact that Laravel 11 dropped dbal as a dependency and removed function we were using from their public api.

• [x] - tests
• [x] - github actions

Packages Missing:

• Media Library Uploads
• Devtools