df704a34f1
``_wait_tasks_ready`` is only called from ``create_job_group_and_request_job``, so it belongs with the other job-group internals (``_create_job_group``, ``_send_job_request``, ``_task_timeout``, ...) rather than next to the task-readiness helpers (``_register_ready``, ``_on_watched_task_ready``).