Add support to set machines in a model using machines() method.

[tkaratug]

This PR adds support to set machines via machines() method in a model in order to use expressions.

Scenario
Let's say we have a column for a machine root event in a table and we want to be able to use different machines based on a condition.

All we need to do is setting machines in machines() method instead of machines property.

protected $fillable = [
    ...
   'column_mre`
];

protected function machines(): array
{
    return [
        'column_mre' => match (true) {
            'condition A' => MachineA::class,
            'condition B' => MachineB::class,
        },
    ];
}

[tkaratug]

Hi Team,

I’m closing this PR because Laravel 11 introduced the ability to perform custom casting directly within the casts() method.

This new feature makes the changes proposed in this PR redundant, as the same functionality can now be achieved in a more integrated way within the framework.