Add UnfulfillableCapacity and InsufficientCapacity in the list of EC2 error codes used for fast fail-over

According to https://docs.aws.amazon.com/AWSEC2/latest/APIReference/errors-overview.html

UnfulfillableCapacity: At this time there isn't enough spare capacity to fulfill your request for Spot Instances. You can wait a few minutes to see whether capacity becomes available for your request. Alternatively, create a more flexible request. For example, include additional instance types, include additional Availability Zones, or use the capacity-optimized allocation strategy.

InsufficientCapacity: There is not enough capacity to fulfill your import instance request. You can wait for additional capacity to become available.

Author: hanwen-cluster

src/slurm_plugin/slurm_resources.py

@@ -223,6 +223,8 @@ class SlurmNode(metaclass=ABCMeta):
         "MaxSpotInstanceCountExceeded",
         "Unsupported",
         "SpotMaxPriceTooLow",
+        "UnfulfillableCapacity",
+        "InsufficientCapacity",
     }
 
     def __init__(