message: Use nydusify to check file content for nydus v6
  At present, the night convert ci test only detects bootstrap,
  and does not detect the content of the file,
  this PR checks the content correctness of the nydus v6 image through nydusify
diff: @@ -53,16 +53,20 @@ jobs:
  done
  - name: Convert and check RAFS v6 images
  run: |
  + sudo docker run -d --restart=always -p 5000:5000 registry
  for I in $(cat ${{ env.IMAGE_LIST_PATH }}); do
  echo "converting $I:latest to $I:nydus-nightly-v6"
  sudo DOCKER_CONFIG=$HOME/.docker nydusify convert \
  --source $I:latest \
  - --target ${{ env.REGISTRY }}/${{ env.ORGANIZATION }}/$I:nydus-nightly-v6 \
  - --build-cache ${{ env.REGISTRY }}/${{ env.ORGANIZATION }}/nydus-build-cache:$I-v6 \
  + --target localhost:5000/$I:nydus-nightly-v6 \
  + --build-cache localhost:5000/nydus-build-cache:$I-v6 \
  --fs-version 6
  sudo rm -rf ./tmp
  - sudo DOCKER_CONFIG=$HOME/.docker nydusify check \
  - --target ${{ env.REGISTRY }}/${{ env.ORGANIZATION }}/$I:nydus-nightly-v6
  + echo "{\"host\": \"localhost:5000\", \"repo\": \"${I}\", \"scheme\": \"http\"}" > backend.json
  + cat backend.json
  + sudo DOCKER_CONFIG=$HOME/.docker nydusify check --source $I:latest \
  + --target localhost:5000/$I:nydus-nightly-v6 \
  + --backend-config-file ./backend.json --backend-type registry
  sudo fsck.erofs -d9 output/nydus_bootstrap
  sudo rm -rf ./output
  done
  