Remove runtime v1

Signed-off-by: Maksym Pavlenko <pavlenko.maksym@gmail.com>

metrics/cgroups/v1/cgroups.go

@@ -28,7 +28,6 @@ import (
 	"github.com/containerd/containerd/log"
 	"github.com/containerd/containerd/namespaces"
 	"github.com/containerd/containerd/runtime"
-	"github.com/containerd/containerd/runtime/v1/linux"
 	"github.com/docker/go-metrics"
 	"github.com/sirupsen/logrus"
 )
@@ -55,11 +54,15 @@ type cgroupsMonitor struct {
 	publisher events.Publisher
 }
 
+type cgroupTask interface {
+	Cgroup() (cgroups.Cgroup, error)
+}
+
 func (m *cgroupsMonitor) Monitor(c runtime.Task, labels map[string]string) error {
 	if err := m.collector.Add(c, labels); err != nil {
 		return err
 	}
-	t, ok := c.(*linux.Task)
+	t, ok := c.(cgroupTask)
 	if !ok {
 		return nil
 	}