cri-o: cri-o v1.18.x is not available on Ubuntu?

Description

cri-o v1.18.x is not available on Ubuntu while v1.15, v1.16, v1.17 are.

Steps to reproduce the issue:

Run as root:

. /etc/os-release
sh -c "echo 'deb http://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable/x${NAME}_${VERSION_ID}/ /' > /etc/apt/sources.list.d/devel:kubic:libcontainers:stable.list"
wget -nv https://download.opensuse.org/repositories/devel:kubic:libcontainers:stable/x${NAME}_${VERSION_ID}/Release.key -O- | apt-key add -
apt-get update -qq

apt-cache search cri-o

Describe the results you received:

OUTPUT:

cri-o-1.15 - OCI-based implementation of Kubernetes Container Runtime Interface.
cri-o-1.16 - OCI-based implementation of Kubernetes Container Runtime Interface.
cri-o-1.17 - OCI-based implementation of Kubernetes Container Runtime Interface.
cri-o-runc - Open Container Project - runtime

Describe the results you expected:

The doc has indicated that all desired versions should be available to install. I’m expecting v1.18 at this moment.

Additional environment details (AWS, VirtualBox, physical, etc.):

$ cat /etc/os-release
NAME="Ubuntu"
VERSION="18.04.4 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.4 LTS"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic