[stable/yoga] tempest.scenario.test_network_qos_placement.MinBwAllocationPlacementTest fails in neutron-ovs-tempest-multinode-full job

[Bernard Cafarelli]

tempest.scenario.test_network_qos_placement.MinBwAllocationPlacementTest.* test fail in a reproducible way in neutron-ovs-tempest-multinode-full job (only for yoga branch).

Sample log failure:
https://storage.bhs.cloud.ovh.net/v1/AUTH_dcaab5e32b234d56b626f72581e3644c/zuul_opendev_logs_0ea/835863/1/check/neutron-ovs-tempest-multinode-full/0ea66ae/testr_results.html
from:
https://review.opendev.org/c/openstack/neutron/+/835863/

From Lajos' review, port-resource-request-groups extension is loaded but it is missing from the api_extensions list

These tests in this job worked in the first days after yoga branching, but are failing since around 2022-03-31:
https://zuul.opendev.org/t/openstack/builds?job_name=neutron-ovs-tempest-multinode-full&project=openstack%2Fneutron&branch=stable%2Fyoga

At first glance I did not see any potential culprit in recent neutron backports, or tempest/neutron-tempest-plugin merged changes

[Lajos Katona (lajos-katona)]

the port-resource-request-groups extension was missing from devstack list, fix:
https://review.opendev.org/c/openstack/devstack/+/836671