Retire the devstack-plugin-zmq project
Retire the devstack-plugin-zmq project

This plugin was used by the oslo.messaging project to test the
development of a message driver based on the ZeroMQ library.

The jobs using this plugin were non-voting and non-gating.

Development of this driver was dropped in Rocky and is not
supported.

Change-Id: I2371dabfa4f50e61a46944e77e8a5b7d3a5997db

openstack-infra/project-config,openstack-infra/project-config