The _lead_apply_status gate was too strict: it only permitted leads to
change task status when the task was already in . This broke
the assignment-and-start shortcut introduced in the wake-assignee
feature, where a lead assigns a worker and simultaneously sets
from .
Allow the transition when the lead is also
supplying an in the same PATCH. All other
non-review status changes remain forbidden.
Fixes test_lead_assignment_and_in_progress_wakes_assignee_once.