Replace docker/distribution/reference with containerd/reference/docker

Since https://github.com/containerd/containerd/pull/3728
The docker/distribution/reference package is copied into containerd core

Signed-off-by: Shengjing Zhu <i@zhsj.me>

pkg/server/helpers_test.go

@@ -24,9 +24,9 @@ import (
 	"github.com/BurntSushi/toml"
 	"github.com/containerd/containerd/oci"
 	"github.com/containerd/containerd/plugin"
+	"github.com/containerd/containerd/reference/docker"
 	"github.com/containerd/containerd/runtime/linux/runctypes"
 	runcoptions "github.com/containerd/containerd/runtime/v2/runc/options"
-	"github.com/docker/distribution/reference"
 	imagedigest "github.com/opencontainers/go-digest"
 	runtimespec "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/stretchr/testify/assert"
@@ -107,7 +107,7 @@ func TestGetRepoDigestAndTag(t *testing.T) {
 		},
 	} {
 		t.Logf("TestCase %q", desc)
-		named, err := reference.ParseDockerRef(test.ref)
+		named, err := docker.ParseDockerRef(test.ref)
 		assert.NoError(t, err)
 		repoDigest, repoTag := getRepoDigestAndTag(named, digest, test.schema1)
 		assert.Equal(t, test.expectedRepoDigest, repoDigest)