refactor(fallback): remove unused code

shiftregister/fallback/models.py

@@ -72,9 +72,6 @@ class TeamMember(models.Model):
         free_bucket = bucket.filter(fallback_count__lt=F("real_required_helpers"))
 
         total_slot_count = bucket.aggregate(sum=Sum("real_required_helpers"))["sum"]
-        free_slot_count = free_bucket.annotate(
-            needed_helpers=F("real_required_helpers") - F("fallback_count")
-        ).aggregate(sum=Sum("needed_helpers"))["sum"]
 
         quota = global_preferences["helper__fallback_quota"]
         number_of_team_members = TeamMember.objects.count()