feat: replace github.com/pkg/errors to errors

Signed-off-by: haoyun <yun.hao@daocloud.io>
Co-authored-by: zounengren <zouyee1989@gmail.com>

errdefs/errors.go

@@ -17,7 +17,7 @@
 // Package errdefs defines the common errors used throughout containerd
 // packages.
 //
-// Use with errors.Wrap and error.Wrapf to add context to an error.
+// Use with fmt.Errorf to add context to an error.
 //
 // To detect an error class, use the IsXXX functions to tell whether an error
 // is of a certain type.
@@ -28,8 +28,7 @@ package errdefs
 
 import (
 	"context"
-
-	"github.com/pkg/errors"
+	"errors"
 )
 
 // Definitions of common error types used throughout containerd. All containerd