[cinder][stable] branch freeze for ocata, pike

tl;dr - do not approve any backports to stable/ocata or stable/pike in any Cinder project deliverable stable/ocata has been tagged with ocata-eol in cinder, os-brick, python-cinderclient, and python-brick-cinderclient-ext. Nothing should be merged into stable/ocata in any of these repositories during the interim period before the branches are deleted. stable/pike: the changes discussed in [0] have merged, and I've proposed the pike-eol tags [1]. Nothing should be merged into stable/pike in any of our code repositories from now until the branches are deleted. [0] http://lists.openstack.org/pipermail/openstack-discuss/2020-July/016076.html [1] https://review.opendev.org/#/c/742523/