[9.x] Defers expanding callables on Factories

[DarkGhostHunter]

What?

When defining attributes on a Factory, this small fix will defer callables to be resolved after all other non-callables are set in the definition array.

This makes this code safe to work with:

public function definition()
{
    return [
        'first' => fn ($attributes) => $attributes['last'] + 1, // 4
        'last' => 3
    ];
}

1. last is resolved first.
2. first will be resolved last.

This avoids making the developer having to push callables to the end of the definition array.