remove clusterapi nodegroupset processor

as discussed with the cluster api community[0], the nodegroupset
processor is being removed from the clusterapi provider implementation
in favor of instructing our community on the use of the
--balancing-ignore-label flag. due to the wide variety of provider
infrastructures that clusterapi can be deployed on, we would prefer to
not encode all of these labels in the autoscaler itself. see the linked
recording for more information.

[0] https://www.youtube.com/watch?v=jbhca_9oPuQ

cluster-autoscaler/main.go

@@ -392,8 +392,6 @@ func buildAutoscaler(debuggingSnapshotter debuggingsnapshot.DebuggingSnapshotter
 		} else if autoscalingOptions.CloudProviderName == cloudprovider.GceProviderName {
 			nodeInfoComparatorBuilder = nodegroupset.CreateGceNodeInfoComparator
 			opts.Processors.TemplateNodeInfoProvider = nodeinfosprovider.NewAnnotationNodeInfoProvider(nodeInfoCacheExpireTime)
-		} else if autoscalingOptions.CloudProviderName == cloudprovider.ClusterAPIProviderName {
-			nodeInfoComparatorBuilder = nodegroupset.CreateClusterAPINodeInfoComparator
 		}
 		nodeInfoComparator = nodeInfoComparatorBuilder(autoscalingOptions.BalancingExtraIgnoredLabels)
 	}