[openstack-helm] gnocchi chart removal

Hey team, One of the topics from the last few PTGs have been reducing the scope of openstack-helm by evaluating which charts were being used and which ones have not been actively maintained and one of those charts that has been discussed was gnocchi. Besides a change to tolerations that was applied to most of the charts in the repo, the gnocchi chart has not seen much activity and there wasn't any immediate interest in maintaining it, so the current plan is to remove it from the repo. If you are someone who is actively using the gnocchi chart and would be interested in helping to maintain it, please let me know!