Hey Scott,
Good news! It's all still there, just not as branches. When a branch is moved from "Extended Maintenance" (EM) to End of Life (EOL), we remove the branch but retain the git refs on a tag.[1] (e.g.
https://opendev.org/openstack/ironic/src/tag/stein-eol is the tag representing Ironic stable/stein at the point of EOL).
Look for the `train-eol` tag on the projects you're struggling with, and that should be the git ref you're looking for. Hopefully your tooling is happy getting any git ref and not just a branch ref.
Thanks,
Jay Faulkner
Ironic PTL
TC Vice-Chair