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

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

runtime/v2/shim_unix.go

@@ -21,6 +21,7 @@ package v2
 
 import (
 	"context"
+	"errors"
 	"io"
 	"net"
 	"os"
@@ -28,7 +29,6 @@ import (
 	"time"
 
 	"github.com/containerd/fifo"
-	"github.com/pkg/errors"
 	"golang.org/x/sys/unix"
 )