Bump kolla-ansible to stackhpc/18.6.0.8

Author: stackhpc-ci

etc/kayobe/stackhpc.yml

@@ -151,7 +151,7 @@ stackhpc_kolla_source_version: stackhpc/{{ openstack_release }}
 
 # Kolla Ansible source repository.
 stackhpc_kolla_ansible_source_url: "https://github.com/stackhpc/kolla-ansible"
-stackhpc_kolla_ansible_source_version: stackhpc/{{ openstack_release }}
+stackhpc_kolla_ansible_source_version: stackhpc/18.6.0.8
 
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 # Container image registry