zuul: layout: AIO: Add openSUSE Leap 42.3 as non-voting CI job
zuul: layout: AIO: Add openSUSE Leap 42.3 as non-voting CI job

openSUSE Leap 42.3 is in the process of getting basic support in AIO
so lets add it as a regular non-voting job as well.

Change-Id: Ie5bae54bac770c1f5114214140c74bed0bb82ad7

openstack-infra/project-config,openstack-infra/project-config