CI: add kolla-ansible zun job to tests

Depends-On: https://review.opendev.org/c/openstack/kolla-ansible/+/954145

Change-Id: I528a141e1a3ff09e820be803c3467952d77b13c6
Signed-off-by: Bartosz Bezak <[email protected]>
(cherry picked from commit fb7a43b)

Author: bbezak

.zuul.d/ubuntu.yaml

@@ -31,6 +31,8 @@
             files: ^docker/proxysql/
         - kolla-ansible-ubuntu-bifrost:
             files: ^docker/bifrost/
+        - kolla-ansible-ubuntu-zun:
+            files: ^docker/|zun/
     check-arm64:
       jobs:
         - kolla-build-ubuntu-aarch64