Workaround the olso master testing job

Applying the same workaround as Sean did for
neutron oslo master job. Details are in

- https://review.opendev.org/c/openstack/neutron/+/948561

Also, adding tempest-full-oslo-master in experimental
pipeline to run it on demand.

Related-Bug: #2109592
Change-Id: I8edbd12c84d8978f2d43ee2aa80bb421c221cdbc

zuul.d/project.yaml

@@ -157,6 +157,7 @@
       jobs:
         - nova-multi-cell
         - tempest-with-latest-microversion
+        - tempest-full-oslo-master
         - tempest-stestr-master
         - tempest-cinder-v2-api:
             irrelevant-files: *tempest-irrelevant-files

zuul.d/tempest-specific.yaml

@@ -30,8 +30,15 @@
       - opendev.org/openstack/oslo.utils
       - opendev.org/openstack/oslo.versionedobjects
       - opendev.org/openstack/oslo.vmware
+      # this is a workaround for a packaging bug in ubuntu
+      # remove when https://bugs.launchpad.net/nova/+bug/2109592
+      # is resolved and oslo config is not a dep of the novnc deb
+      # via the defunct python3-novnc package.
+      - novnc/novnc
     vars:
       tox_envlist: full
+      devstack_localrc:
+         NOVNC_FROM_PACKAGE: false
 
 - job:
     name: tempest-full-parallel