fix: deleting empty planned work shifts

services/work_shifts_planning.py

@@ -74,7 +74,10 @@ class WorkShiftsPlanningService(BaseService):
             )
             self.session.add(work_shift)
         else:
-            work_shift.positions = positions
+            if len(positions) == 0:
+                await self.session.delete(work_shift)
+            else:
+                work_shift.positions = positions
 
         await self.session.commit()