Implement a CI/CD integration for Forgejo

[tsteenbe]

Similar to the ORT integrations for GitHub and GitLab we propose to implement a integration for Forgejo Actions.

[sschuberth]

As a side note, my (current) favorite Linux distribution, Fedora, is moving to Forgejo as well, probably giving it some traction in general. Also, Berlin-based CodeBerg is a popular Forgejo hoster, and it hosts Forgejo itself.

[sschuberth]

Generally, as briefly mentioned in today's TSC meeting, the growing number of integrations we have for ORT makes me think whether we should move all integration into a separate GitHub org (like "oss-review-toolkit-integrations"), given GitHub's limited (i.e. non-existing) capabilities to group projects within an org. That would also ease permission management for the main "oss-review-toolkit" org.

[tsteenbe]

Moving the integrations out of the GitHub org will hurt ORT user/contributor growth - new users will expect the CI/CD integrations to be part of oss-review-toolkit org like many other project. I am sure GitHub permission management challenges can be sorted out - if github.com/cncf with 160+ repositories maintained by tens of maintainers from different backgrounds then in comparison tiny ORT project should be able to do same.