Those are remnants from the oslo-incubator times. Also, oslo.messaging
deprecated [1] transport aliases since 5.2.0+ that is the minimal
version supported for stable/newton. The patch that bumped the minimal
version for Neutron landed 3 months+ ago, so we can proceed ripping
those aliases from the code base.
[1] I314cefa5fb1803fa7e21e3e34300e5ced31bba89
Change-Id: I9e66140ad0b10c50e216c78e4914c98313cada05
Closes-Bug: #1424728