Close all open issues and archive this repo on Github

[jamillambert]

The move to Forgejo has been done and no new PRs are already allowed here. Should we take the next step of closing all open issues, except the migration marker, and archive the repo on Github to prevent any PR or issue from being opened here?

[tcharding]

On other repos we discussed leaving the repo open so that drive by contributors can raised issues. github is more visible and these issues can be valuable. I think we should do the same here. It does mean manually cloning new issues over but that is the best we can do at the moment from what I've worked out.