`tar` fails on Windows, and the exit code is ignored

When trying to create tarballs on Windows, it fails like this. And the exit code is being explicitly ignored which means the issue isn't caught.

1. Is `tar` known not to work well on windows?
2. Why is the exit code being ignored and instead of letting it fail the build?

build: https://dev.azure.com/dnceng/internal/_build/results?buildId=2753219&view=logs&j=0bc77094-9fcd-5c38-f6e4-27d2ae131589&t=5138e247-88cb-5ba0-8eee-e2fdd127e7e8