ceph-container releases don't follow the ceph releases. You don't always have a
ceph-container release matching a ceph release.
ceph-container releases are based on the changes in the ceph-container code.
At the moment there's only one commit present on the stable-4.0 branch since v4.0.15
release so I'm not sure it worth creating a release for this in order to have an
updated ceph version especially since ceph-volume (lvm batch) is broken in 14.2.13 and
14.2.14.
But you can still use the latest-nautilus container image tag if you want.
$ docker run --rm --entrypoint ceph ceph/daemon:latest-nautilus --version
ceph version 14.2.14 (7e94c5afc28f3eaf36151ad1e1457de5f16c4fdf) nautilus (stable)