fix(hetzner): unused draining node pool references deprecated server …

…type

The `cx11` server type was deprecated on 2024-06-06 and will be removed
from the API on 2024-09-06. Once it is removed, the cluster-autoscaler
provider hetzner will not start anymore with the following error
message:

    Failed to get node infos for groups: failed to create resource list for node group draining-node-pool error: failed to get machine type cx11 info error: server type not found

As the node pool `draining-node-pool` is not being used anywhere, this
commit removes it and the hard coded reference to the deprecated server
type.

cluster-autoscaler/cloudprovider/hetzner/hetzner_cloud_provider.go

@@ -41,7 +41,6 @@ const (
 	providerIDPrefix           = "hcloud://"
 	nodeGroupLabel             = hcloudLabelNamespace + "/node-group"
 	hcloudLabelNamespace       = "hcloud"
-	drainingNodePoolId         = "draining-node-pool"
 	serverCreateTimeoutDefault = 5 * time.Minute
 	serverRegisterTimeout      = 10 * time.Minute
 	defaultPodAmountsLimit     = 110

cluster-autoscaler/cloudprovider/hetzner/hetzner_manager.go

@@ -154,16 +154,6 @@ func newManager() (*hetznerManager, error) {
 		cachedServers:    newServersCache(ctx, client),
 	}
 
-	m.nodeGroups[drainingNodePoolId] = &hetznerNodeGroup{
-		manager:      m,
-		instanceType: "cx11",
-		region:       "fsn1",
-		targetSize:   0,
-		maxSize:      0,
-		minSize:      0,
-		id:           drainingNodePoolId,
-	}
-
 	return m, nil
 }
 
@@ -200,11 +190,6 @@ func (m *hetznerManager) deleteServer(server *hcloud.Server) error {
 	return err
 }
 
-func (m *hetznerManager) addNodeToDrainingPool(node *apiv1.Node) (*hetznerNodeGroup, error) {
-	m.nodeGroups[drainingNodePoolId].targetSize += 1
-	return m.nodeGroups[drainingNodePoolId], nil
-}
-
 func (m *hetznerManager) validProviderID(providerID string) bool {
 	return strings.HasPrefix(providerID, providerIDPrefix)
 }