[5.x] Support rendering model attributes in Antlers

[ryanmitchell]

This PR ensures Laravel model attributes can be rendered in antlers without having to add them to appends().

This allows you to do things like:

class MyModel extends \Illuminate\Database\Eloquent\Model
{
    public function fooBar(): Attribute
    {
        return Attribute::make(
            get: fn() => 'FooBar',
        );
    }
}

{{ my_model:foo_bar }}

I hope I did this right and @JohnathonKoster approves of the approach.

Closes #7356