automate Rust crates

[cgwalters]

• Use https://crates.io/docs/trusted-publishing
• Also automate releases (xref a bit discussion in https://www.reddit.com/r/rust/comments/1lxux2p/cratesio_development_update_trusted_publishing/)

[cgwalters]

cc @jeckersb

[champtar]

+1 for Trusted publishing / automation, but we should still have a group of owner for each crate, so we never lose access and can yank a release, edit the infos on crates.io, setup trusted publishing v2 in the future, ...

[cgwalters]

Yep agree we should have a bootc-crates-owners team on crates.io whose identity is sync'd with a Github team here or so.

[cgwalters]

First step: https://crates.io/teams/github:bootc-dev:crates-owners now exists and owns the crates published from here.