Currently there is no support for the cluster upgrade-action.

API doc:

• https://docs.openstack.org/api-ref/container-infrastructure-management/?expanded=upgrade-a-cluster-detail#upgrade-a-cluster

source from cluster-actions controller:

• https://github.com/openstack/magnum/blob/e8467e94d88b6feb67ff7c167f5e167cd452c772/magnum/api/controllers/v1/cluster_actions.py#L58
• https://github.com/openstack/magnum/blob/e8467e94d88b6feb67ff7c167f5e167cd452c772/magnum/api/controllers/v1/cluster_actions.py#L132