If2608406776e0d5a06b726e65b55881e70562d18 dropped the single node
grenade job from the integrated-gate-compute template as it duplicates
the existing grenade-multinode job. However it doesn't remove the
remianing single node grenade job still present in the Nova project.
This change replaces the dsvm based nova-grenade-multinode job with the
zuulv3 native grenade-multinode based job.
Various legacy playbooks and hook scripts are also removed as they are
no longer used. Note that this does result in a loss of coverage for
ceph that should be replaced as soon as a zuulv3 native ceph based
multinode job is available.
Change-Id: I02b2b851a74f24816d2f782a66d94de81ee527b0
91e53e4c2b