Feature request: Forgejo / Gitea actions support

[justyns]

Similar to the github support mentioned on https://opencode.ai/docs/github/, it would be nice if there was also support for forgejo/gitea actions. They are somewhat compatible with github actions, but I'm assuming opencode itself would need custom logic for using the forgejo api for comments/prs/etc instead of github's.

Ref:

• https://forgejo.org/docs/latest/user/actions/github-actions/