This commit improves our small publish script for Wasmtime with the goal
of being able to run it on CI. This fixes a few issues with the current
script such as:
* If you rerun the script it won't try to republish crates already
published.
* Once a crate is published it won't print an error trying to re-add the
`wasmtime-publish` owner group.
* This will automatically retry publishing crates if they fail to get
published, hopefully handling issues like rate limiting and/or waiting
for the index to update.
The eventual goal is to run this script on a tag automatically on CI so
we don't have to do it manually, and these changes should make the
script more robust to run on CI and also makes it so we can inspect
failure outputs and rerun it locally.
For now these changes aren't heavily tested since it's somewhat
difficult to do so, so for now I figure we'll need to babysit the next
release or two with this script.
319e1c6e16