Fix the integrated-gate-compute job template

Below commit changed the integrated-gate-compute job template
behaviour for stable branches. This template is used for master
as well as the stable branches also and we should not change
stable branches gate while adding the new jobs. centos-8-stream
job is meant to be run from stable/wallaby to stable/yoga and
from zed cycle onwards centos-9-stream should run,

- https://review.opendev.org/c/openstack/tempest/+/839274/1/zuul.d/integrated-gate.yaml#369

This commit fixes the template for stable branches and make sure
new job centos9-stream is only run from zed onwards.

Change-Id: I15b44aff4ab633cf7ab39cbb4fc56a027d29544e
1 file changed