Comment 4 for bug 1938807

Reviewed: https://review.opendev.org/c/openstack/charm-ceilometer/+/816150
Committed: https://opendev.org/openstack/charm-ceilometer/commit/f4d772e6a3af21d7917aec60e8ab8b93eaba3688
Submitter: "Zuul (22348)"
Branch: master

commit f4d772e6a3af21d7917aec60e8ab8b93eaba3688
Author: Arif Ali <email address hidden>
Date: Mon Nov 1 08:05:32 2021 +0000

    Enable pipeline_yaml for mitaka and above

    This configuration for pipeline.yaml is still valid for mitaka and
    above, so adding this in.

    The ceilometer-collector package is not available in newer openstack
    releases, so basing this on QUEENS_SERVICES.

    This should solve the custom requirement of pipeline moving forward.

    Other fixes:
    * Update test-requirements.txt for cffi and related pins.
    * Update focal-xena bundle to fix memcached series bionic requirement.

    Closes-Bug: 1938807
    Change-Id: I1946b6f172cdae6f444d07999d5e54d4e11a450e