If package or SHA download from pkgs.tailscale.com fails with a non-200
repsonse code, make the whole action fail. This catches things like
incorrect versions.
Updates #118
We periodically have reports of failures in the GitHub Action
where there has been no recent change in Tailscale infrastructure
and no indication of a problem in metrics or monitoring.
Right now we have to generate a pull request to get this test
workflow to run. Allow it to be run manually whenever desired.
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
