Allow Bus::batch to be chained

[EternalPlanemo]

The documentation has a snippet for a chained batch, but as far as I'm aware this has never been a feature.

https://laravel.com/docs/10.x/queues#chains-and-batches

use App\Jobs\FlushPodcastCache;
use App\Jobs\ReleasePodcast;
use App\Jobs\SendPodcastReleaseNotification;
use Illuminate\Support\Facades\Bus;
 
Bus::chain([
    new FlushPodcastCache,
    Bus::batch([
        new ReleasePodcast(1),
        new ReleasePodcast(2),
    ]),
    Bus::batch([
        new SendPodcastReleaseNotification(1),
        new SendPodcastReleaseNotification(2),
    ]),
])->dispatch();

Batch does not have a ::chain() method

[ahinkle]

It was introduced in v10.31. #48633