zuul: Remove devstack-plugin-ceph-tempest job

This job is now failing 100% of the time on master since the EOL of py2:

https://zuul.opendev.org/t/openstack/builds?job_name=devstack-plugin-ceph-tempest&branch=master

Change-Id: I0bb03190f39b5ae5494b2d10a0e819013d60bddf

Author: lyarwood

.zuul.yaml

@@ -695,10 +695,6 @@
         - neutron-fullstack-with-uwsgi
         - neutron-functional-with-uwsgi
         - neutron-tempest-with-uwsgi
-        - devstack-plugin-ceph-tempest:
-            irrelevant-files:
-              - ^.*\.rst$
-              - ^doc/.*$
         - devstack-plugin-ceph-tempest-py3:
             irrelevant-files:
               - ^.*\.rst$