chore(CI): allow push to crates.io for version tag

[fMeow]

Current workflow require manual action by @moriturus when publishing new version to crates.io.

This PR enable github action to push new version to crates.io for version tag (e.x. v0.6.0, v0.1.2). With Actions secrets, we can publish to crates.io with token configured before hand without leaking.

Now the only missing piece is a valid cargo token. This require repo owner @moriturus to setup secret in repo settings actions secret page(only repo owner can open this link).
I named the cargo token CARGO_TOKEN and here is a snapshot of another repo that has correctly setup cargo token in action secrests.

Here I call for @moriturus to manually add CARGO_TOKEN to repo setting.

Thanks a lot.

[gagbo]

The tags we use for now don't start with v, so either

• we start using v{MAJOR}.{MINOR}.{PATCH} now, or
• we match against refs/tags/ instead

I don't have any strong opinion on the matter.

[gagbo]

You might as well create a new workflow file called publish.yml that would deal exclusively with cargo publishing step.

That would allow (you, me, or someone else) later to add a "check" step that ensures the tag on github matches the version in the Cargo.toml before publishing (it's something that is easy to check and easy to forget, so it's a nice addition to the workflow imo)

[fMeow]

Sounds good.

I suggest match against refs/tags/ and create a new publish workflow which requires manual trigger.

[fMeow]

I personllay think to safer to run through all test before publish. But might clean the publish workflow to publish related pipeline only.

[gagbo]

No worries there, only blocked by access to repo settings