Setup release process for Turtles Providers chart

[alexander-demicev]

Turtles Providers chart was added recently and integrated into our CI but there is no release process. Short summary of what needs to be done:

• Add new release workflow, the chart will have a separate release cycle, it doesn't depend on Turtles tag/releases. The chart should be published as OCI artifact in prime registry, that would require an EIO ticket.
• Document the release process for this chart in docs/release.md

[moio]

@alexander-demicev FYI we now have https://github.com/rancher/prime-charts to release Prime-only Helm Charts as OCI to registry.suse.com/rancher/charts. Automation should look and feel very similar to the existing one.

A Slack channel will be created for coordination on this topic