Comment 3 for bug 1977888

dib is dropping support for <py3.8 [1] with Zed release.
dib is branchless, so we're pulling master.

tripleoclient [2] for train still supports py3.6 and py3.7

[1]: https://github.com/openstack/diskimage-builder/commit/fe0e5324d4248d114660ec35111ae9601e05b95b
[2]: https://github.com/openstack/python-tripleoclient/blob/stable/train/setup.cfg#L22