For partitionable slots, VOFE will stop too early
Partitionable slots always appear to be idle, so we may stop sending jobs to a site too early (it looks like there are many idle glideins, when it just the partitionable slots). A partitionable slot has no more resources to dole out when TotalSlots =?= 1
As a first iteration, we should add a constraint to only count slots as idle if the following expression is true:
((PartitionableSlot =!= True) || (TotalSlots =?= 1))
For a second iteration -- imagine that all the user jobs that the FE can see ask for 8 CPUs. Imagine the partitioanble slot has 4 subslots remaining (TotalSlots == 5). To our system, the partitionable slot isn't idle since we can't match any jobs to it.