[10.x] Fix Factory::afterCreating callable argument type

[villfa]

The callback passed as an argument to afterCreating() is always invoked with 2 parameters, the 2nd parameter being the parent model (see callAfterCreating()).

Before this change, PHPStan could raise this kind of error:

 Parameter #1 $callback of method Illuminate\Database\Eloquent\Factories\Factory<Illuminate\Database\Eloquent\Model>::afterCreating() expects Closure(Illuminate\Database\Eloquent\Model): mixed, Closure(App\Models\MyModel, mixed): void given.  
 🪪  argument.type                                                                                                                                                                                                                                  
 💡 Parameter #2 $parent of passed callable is required but accepting callable does not have that parameter. It will be called without it. 

Here're some reproducers:

• Before: https://phpstan.org/r/8943ed79-f8b5-4b24-89af-76d82e044977
• After: https://phpstan.org/r/8120c644-077f-4e92-8113-749f41aa00d4