[13.x] Push batched jobs to their own queue when the batch has no queue

[xurshudyan]

When a batch is dispatched without onQueue(), every job goes to the default queue even if the job itself set a queue:

Bus::batch([
    (new ResizeImage($photo))->onQueue('images'),
])->dispatch();

// jobs.queue = "default", a worker on --queue=images never picks it up

With this change the job goes to images. Bus::batch()->onQueue() still applies to every job as before, so existing batches are not affected.

[jackbayliss]

Seems odd to me to do this within a batch?