message: nydusify/util: support image with platform linux/arm64
  Currently, nydusify only fetch image with platform linux/amd64.
  It can fetch right arm64 image if it is running on arm machine
  Note: containerd decompression package might use `unpigz` to decompress
  gzip, which can lead to an invalid tar file. So avoid enabling `pigz`
diff: @@ -10,6 +10,7 @@ import (
  "fmt"
  "io"
  "os"
  + "runtime"
  "time"
  "github.com/containerd/containerd/archive/compression"
  @@ -19,7 +20,7 @@ import (
  )
  const SupportedOS = "linux"
  -const SupportedArch = "amd64"
  +const SupportedArch = runtime.GOARCH
  const defaultRetryAttempts = 3
  const defaultRetryInterval = time.Second * 2
  