Allow empty networking.nodes in case of IPv6 only shoots. (gardener…

…#10533)

pkg/gardenlet/operation/shoot/shoot.go

@@ -577,7 +577,7 @@ func ToNetworks(shoot *gardencorev1beta1.Shoot, workerless bool) (*Networks, err
 			return nil, fmt.Errorf("cannot parse shoot's node cidr %w", err)
 		}
 		nodes = append(nodes, *n)
-	} else if !workerless {
+	} else if !workerless && !gardencorev1beta1.IsIPv6SingleStack(shoot.Spec.Networking.IPFamilies) {
 		return nil, fmt.Errorf("shoot's node cidr is empty")
 	}