With the new release identification / naming schema [1] (like:
2023.1 Antelope) new stable branch naming was introduced (like:
stable/2023.1). This was not accepted in the validator command.
Previously the validator was fixed for 'std' and 'std-with-versions'
branching typed deliverables, but missed the 'tagless' deliverables
case. This patch fixes this by accepting the new branch naming style,
stable/<release-id>, for tagless deliverables, too.
[1] https://governance.openstack.org/tc/reference/release-naming.html
Change-Id: I6ba51454213e095e6b76e0813dab3ce44b1457ba
32c9bc69eb