Unfortunately this patch has to include two unrelated changes, otherwise
jobs fail and separate patches could not be merged.
Sphinx version needs to be pinned to 4.4.0 (or earlier), because new
version 7.0.0 causes some issues.
Due to recent changes in devstack-plugin-ceph, the
devstack-tobiko-storage-ceph job failed with ubuntu focal nodes, so its
nodeset has to be modified to use jammy instead.
This patch also updates to ubuntu jammy other jobs that pass with those
nodes. However, some other tobiko jobs need to keep on using ubuntu
focal: more specifically, those jobs running scenario tests on Ubuntu
VM instances fail with jammy nodes.
Change-Id: I955beb104db24377a697b1bccad66ab14fe66568
