Publish crates to crates.io

[robinhundt]

When the crates are in a suitable (which is?) state, we should publish seec to crates.io. Ideally, this is done automatically via CI when a new github release is created.

Relevant material:

• cargo release https://github.com/crate-ci/cargo-release
• A guide on cargo release https://opensource.axo.dev/cargo-dist/book/workspaces/cargo-release-guide.html

Edit: I think when using cargo release no CI action is necessary.