[11.x] Set HasAttributes@casts() array generics

[cosmastech]

I keep having to add this type-hint to my models on a project. Figured I would help myself (and others) out.

[Jubeki]

As the array does not only contain strings, but could also contain a custom cast like https://laravel.com/docs/11.x/eloquent-mutators#custom-casts, this would be better in my opinion.

Sorry my bad, it will still be referenced as a class string.