fix: clusterGet no error on no lb config

- clusterGet should not return an error, if it cannot get the
loadbalancer config, as it's not critical
  -> it should not rely on files created in nodehook actions
- this also fixes a nil pointer exception when cluster creation was
interrupted even before the loadbalancer was added to the cluster in
memory

Fixes #683

pkg/client/cluster.go

@@ -794,10 +794,10 @@ func ClusterGet(ctx context.Context, runtime k3drt.Runtime, cluster *k3d.Cluster
 			}
 		}
 
-		if cluster.ServerLoadBalancer.Node != nil {
+		if cluster.ServerLoadBalancer != nil && cluster.ServerLoadBalancer.Node != nil {
 			lbcfg, err := GetLoadbalancerConfig(ctx, runtime, cluster)
 			if err != nil {
-				return cluster, fmt.Errorf("error getting loadbalancer config for cluster %s: %w", cluster.Name, err)
+				log.Errorf("error getting loadbalancer config from %s: %v", cluster.ServerLoadBalancer.Node.Name, err)
 			}
 			cluster.ServerLoadBalancer.Config = &lbcfg
 		}