pulp: Stop syncing prometheus-jiralert image

We no longer support it.

Author: markgoddard

etc/kayobe/pulp.yml

@@ -497,7 +497,6 @@ stackhpc_pulp_images_kolla:
   - prometheus-blackbox-exporter
   - prometheus-cadvisor
   - prometheus-haproxy-exporter
-  - prometheus-jiralert
   - prometheus-libvirt-exporter
   - prometheus-memcached-exporter
   - prometheus-msteams