Open Stack

I have changes up which move the nova-cells-v1 CI job to the 
experimental queue:

https://review.openstack.org/#/q/topic:bug/1807407

We continue to see intermittent failures in that job and given the 
deprecated nature of cells v1, CERN is using cells v2, the job no longer 
runs nova-network, and its flakiness (plus the general state of the gate 
lately), it is time to move this further out of our daily lives and down 
the road to its eventual removal. Keeping it as an option to run 
on-demand in the experimental queue at least allows us to leverage it if 
needed should some major cells v1 fix be needed, but that is doubtful 
(we haven't had a cells v1 specific bug fix in a long time).

-- 

Thanks,

Matt