Switch to opensuse-15 nodeset
Switch to opensuse-15 nodeset

opensuse-150 nodeset is referring to openSUSE 15.0, which is still in
maintenance but openSUSE 15.1 has been released already. "opensuse-15"
is going to refer to the "latest openSUSE 15.x" build released and
working for OpenStack going forward, so add this nodeset and use
it by default going forward.

Depends-On: https://review.opendev.org/#/c/689323/
Change-Id: I791eb263daca896aa4538f38938b43f2a4a75b5c

openstack/openstack-ansible-galera_client,openstack/openstack-ansible-galera_client