idle-crafting: cancel orphaned jobs

[myk002]

idle-crafting appears to be "stuck" in my test fort
a craft job is enqueued for a specific (active military) unit, but that unit is currently leading a dodging demonstration instead
once I switched the squads to the Ready schedule, that unit started taking other jobs, like moving items to a stockpile
I think we might need a failsafe check that removes an idle crafting job if the target unit is doing something else
this may have been caused initially by that unit being in the active military
(or maybe becoming active military after the crafting job was created, not sure)