[CI] Remove not defined job from queue

Among zuul configuration errors there is the following error:
- Job ironic-grenade-dsvm-multinode-multitenant not defined [1]

This patch removes this job to get rid of the zuul config error.

[1] https://zuul.opendev.org/t/openstack/config-errors?project=openstack%2Fnetworking-generic-switch

Change-Id: I51905f76298598c109afd6509e7aa7b6b9835ed1
(cherry picked from commit bc3511f)

Author: Elod Illes

zuul.d/project.yaml

@@ -17,10 +17,6 @@
               - ^tools/.*$
               - ^tox.ini$
               - ^setup.cfg$
-        # NOTE(rpittau): temp disabling job until all changes
-        # for ussuri are completed
-        - ironic-grenade-dsvm-multinode-multitenant:
-            voting: false
         - networking-generic-switch-tox-codespell:
             voting: false
     gate:
@@ -36,6 +32,3 @@
               - ^tools/.*$
               - ^tox.ini$
               - ^setup.cfg$
-        # NOTE(rpittau): temp disabling job until all changes
-        # for ussuri are completed
-        # - ironic-grenade-dsvm-multinode-multitenant