Documentation for `role-to-assume`

[GrantBirki]

👋 Hi there!

I have a few projects that use GitHub Action's to publish to RubyGems. I am trying to adapt my projects to use the new "Trusted Publishing" via OIDC and want to adopt this Action in my workflow. My workflows are unique and I cannot just use the standard release-gem workflow.

I was looking over the docs here and it is not clear to me where the role-to-assume values come from. I'm looking for some updated documentation around this value in the following ways:

• I see in the docs that role-to-assume can be 2 or 3. What do these numbers mean?
• Where do these values come from?
• What are the key differences between these "roles"?
• What are the bare minimum roles / values that need to be provided for a GitHub Actions workflow to push a new Gem version to RubyGems.

Thanks! 🙇

[GrantBirki]

Gentle nudge to @hsbt for help here? 🙇