tasks: Work around podman 3.0.0 volume handling regression
tasks: Work around podman 3.0.0 volume handling regression

Current podman 3.0.0 in system mode has a regression with handling
anonymous volumes. See https://github.com/containers/podman/issues/9432
for details.

Work around this by placing RabbitMQ's data into a tmpfs volume.

cockpit-project/cockpituous,cockpit-project/cockpituous