The task used by ingest-raws can support multiprocessing but the command line can't supply it. Add the option.
Should be a quick review. I imagine I should remove the option from ctrl_mpexec on this ticket as well and use the daf_butler variant.
This looks great. It would be best if you changed ctrl_mpexec too, the way you suggest. I'll mark this as reviewed, but would appreciate it if you go ahead & do ctrl_mpexec too.