add publish job and dry-run to CI

[HEnquist]

Adds a cargo publish --dry-run --workspace job. Should have put this in the first CI PR,
I've found it very helpful.

• --workspace verifies azo against the locally packaged azo-sys instead of the version
  on crates.io, so the two crates are checked as the coordinated release they actually are
• catches packaging problems that clippy can't see, like a tarball that doesn't build standalone

I can also add a real publish job triggered when cutting a release, if you want that. I prefer
running publish from the repo, that way I know everything I publish is committed and pushed.

[LastExceed]

I can also add a real publish job triggered when cutting a release

This sounds good, but what exactly do you mean by "cutting a release" ?

[HEnquist]

Haha fair question!
My process is to get all the changes I want to include merged to main, including bumping the version numbers. The CI runs the publish dry-run, so I know cargo publish is likely to work. Then I create a release on github ("draft new release" button, should be here: https://github.com/LastExceed/azo/releases), and let GitHub autogenerate release notes. And then the new release triggers a publish job that runs cargo publish. That uses a crates.io key that I store in the repo secrets.

Example workflow:
https://github.com/HEnquist/audioadapter-rs/blob/master/.github/workflows/publish.yml

[LastExceed]

Oh this is a great idea, yes please do add that!

[HEnquist]

Added the publish workflow as a separate file, .github/workflows/publish.yml. It triggers
on tag pushes, which is what creating a GitHub release does.

Two things to set up before the first release:

1. A token on crates.io, under Account Settings > API Tokens > New Token. The publish-new and
   publish-update scopes are enough, and you can restrict it to azo and azo-sys.
2. That token in the repo, under Settings > Secrets and variables > Actions > New repository
   secret, named exactly CARGO_REGISTRY_TOKEN.

The trigger is tags: ['*'], so any tag publishes. If you'd rather only publish on version
tags, change it to 'v*', or 'v[0-9]+.[0-9]+.[0-9]+' to be strict about vX.Y.Z.

It runs cargo publish --workspace, which publishes azo-sys first and waits for it to land on
the index before azo. The job goes red if anything fails.

[LastExceed]

...and just as I wanted to merge this, I encountered the very reason I need this: I have released v0.0.9 yesterday without pushing the commit from which I released, and have since merged your other PRs, which means master has diverged +.+

In order to preserve the release commit I had to rebase origin/master onto my local master and force-push it, can you rebase your PR onto that please?

Thanks for proactively making sure this won't happen again lol

[LastExceed]

Oh and please do limit the trigger to version tags as you described while you're at it

[HEnquist]

Done and done :)

[LastExceed]

tyvm!