fix: change WorkloadResourceQuantity fields to be nullable

Author: rbjornstad

schema.graphql

@@ -6252,10 +6252,10 @@ enum WorkloadOrderField {
 """Resource quantities for a workload."""
 type WorkloadResourceQuantity {
   """The number of CPU cores."""
-  cpu: Float!
+  cpu: Float
 
   """The amount of memory in bytes."""
-  memory: Int!
+  memory: Int
 }
 
 """Interface for resources allocated to workloads."""