Remove features and design that supports adding OSDs to Ceph clusters
via `spec:driveGroups`. Update the Ceph upgrade doc that informs users
who currently use Drive Groups (we believe there are none of these
users) how to migrate to using the `spec:storage` config.
Resolves https://github.com/rook/rook/issues/7275
Revert "ceph: fix drive group deployment failure"
This reverts commit 76f1d9944e.
Revert "ceph: osd: add drive groups spec to cluster CR"
This reverts commit 7117fc12b7.
Revert "design: ceph orchestrator module add/remove OSDs"
This reverts commit 178187d035.
Signed-off-by: Blaine Gardner <blaine.gardner@redhat.com>