The Go code has two archivers.
https://godoc.org/go.chromium.org/luci/client/archiver#TarringArchiver
https://godoc.org/go.chromium.org/luci/client/archiver#Archiver

AIs:
- Only one should be kept.
- The tool isolated should use the same as 'isolate' which is currently not the case.


Ref:
https://chromium.googlesource.com/infra/luci/luci-go/+/44ec31d1076c4f57e848afd199a8cf9f0ab30af5/client/cmd/isolated/archive.go#98
https://chromium.googlesource.com/infra/luci/luci-go/+/44ec31d1076c4f57e848afd199a8cf9f0ab30af5/client/cmd/isolate/batch_archive.go#167