Fix: Allow scale to zero during cluster deletion.

Author: kash2104

ray-operator/controllers/ray/utils/util.go

@@ -389,6 +389,10 @@ func GetWorkerGroupDesiredReplicas(workerGroupSpec rayv1.WorkerGroupSpec) int32
 	if workerGroupSpec.Suspend != nil && *workerGroupSpec.Suspend {
 		return 0
 	}
+	//Required to ensure all workers are shutdown when replicas is set to 0 before deleting the raycluster
+	if workerGroupSpec.Replicas != nil && *workerGroupSpec.Replicas == 0 {
+		return 0
+	}
 	if workerGroupSpec.Replicas == nil || *workerGroupSpec.Replicas < *workerGroupSpec.MinReplicas {
 		// Replicas is impossible to be nil as it has a default value assigned in the CRD.
 		// Add this check to make testing easier.