[11.x] feat: improve Factory generics, add generics to HasFactory

[calebdw]

Hello!

This PR updates the Factory generics to make the types more accurate. I also added generics to the HasFactory trait, as well as allow the user to define a static $factory property in lieu of overriding the newFactory method which helps slim down models. Of course the method can still be overridden if desired.

// before
class User extends Authenticatable
{
    use HasFactory;

    protected function newFactory(): UserFactory
    {
        return UserFactory::new();
    }
}

// after
class User extends Authenticatable
{
    /** @use HasFactory<UserFactory> */
    use HasFactory;

    protected static string $factory = UserFactory::class;
}

Thanks!

[Jubeki]

Because I know, that PHP-CS-Fixer and Pint can have problems with formatting / ordering traits with comments in between, I wanted to ask, if the following is possible too:

/** @use HasFactory<UserFactory> */
class User extends Authenticatable
{
    use HasFactory;
}

Great work!!! ❤️

[calebdw]

@Jubeki, no it looks like placing @use on the class level does not work:

 ------ -------------------------------------------------------------------------------------------------------------------------- 
  Line   Autoload.php                                                                                                              
 ------ -------------------------------------------------------------------------------------------------------------------------- 
  15     Class User uses generic trait Illuminate\Database\Eloquent\Factories\HasFactory but does not specify its types: TFactory  
         🪪  missingType.generics                                                                                                  
 ------ -------------------------------------------------------------------------------------------------------------------------- 

For what it's worth though, I've never had ordering issues with Pint (uses PHP-CS-Fixer) so that could be fixed.

[Jubeki]

@calebdw I checked again, it seems I remembered incorrectly. It was a spacing issue and not an ordering issue: laravel/pint#278
So should be no problem!

[calebdw]

Thanks @taylorotwell!