mv internal/testutil pkg/testutil

The package is consumed by several snapshotter plugins

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

pkg/archive/issues_test.go

@@ -24,8 +24,8 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/containerd/containerd/v2/internal/testutil"
 	"github.com/containerd/containerd/v2/pkg/archive/compression"
+	"github.com/containerd/containerd/v2/pkg/testutil"
 )
 
 // TestPrefixHeaderReadable tests that files that could be created with the