ci: Enable releasing to crates.io via CI
Adapt GitLab CI, so that using a token from the environment can be used for releasing to crates.io on the default branch and a tag pipeline. Adjust cocogitto's configuration to no longer publish to crates.io.
Due to an influx of spam, we have had to temporarily disable account registrations. Please write an email to accountsupport@archlinux.org, with your desired username, if you want to get access. Sorry for the inconvenience.
Adapt GitLab CI, so that using a token from the environment can be used for releasing to crates.io on the default branch and a tag pipeline. Adjust cocogitto's configuration to no longer publish to crates.io.