Add nova ceph jobs for more coverage

Nova ceph jobs are using this plugin/ceph base
jobs with more configs and test coverage. Change
in this plugin can break Nova gate which is critical
if it happens during release time.

It is better to test those jobs as part of check pipeline.

Recent failure - https://zuul.opendev.org/t/openstack/builds?job_name=nova-live-migration-ceph&skip=0

Depends-On: https://review.opendev.org/c/openstack/nova/+/977150

Change-Id: I90fef962355c7237b8042b5970275afef43ffb7f
Signed-off-by: Ghanshyam Maan <gmaan.os14@gmail.com>

.zuul.yaml

@@ -142,6 +142,8 @@
       jobs:
         - devstack-plugin-ceph-tempest-py3
         - devstack-plugin-ceph-multinode-tempest-py3
+        - nova-live-migration-ceph
+        - nova-ceph-multistore
         - devstack-plugin-ceph-multinode-cephfs-nfs-cephadm:
             irrelevant-files: *irrelevant-files
             voting: false