Add CarbonSetTestNowToTravelToRector rule

[tamiroh]

Summary

This pull request proposes CarbonSetTestNowToTravelToRector which replace Carbon::setTestNow() with $this->travelTo(). This would make the following change.

use Illuminate\Foundation\Testing\TestCase;

class SomeTest extends TestCase
{
    public function test()
    {
-       Carbon::setTestNow('2024-08-11');
+       $this->travelTo('2024-08-11');
    }
}

Motivation

• $this->travelTo() is simpler. 👍
• When using Carbon in Laravel applications, we often confuse Carbon\Carbon and Illuminate\Support\Carbon. $this->travelTo() prevents it.
• Carbon\Carbon::setTestNow() does not mock the result of Carbon\CarbonImmutable::now(). On the other hand, $this->travelTo() mocks both.