RHEL Docker Container for Use in Pipelines

In case someone finds this useful, in the ros-controls group we created a RHEL-based (actually alma-linux) docker image that we use to check our packages for RHEL compatibility since the ros build-farm now builds RPMs for RHEL. You can find the repo on github at ros-controls/ros2_rhel and pull the image using the tag ghcr.io/ros-controls/ros:<DISTRO>-rhel as described in the README.md as found in the repository. Feel free to use the image in your pipelines and provide feedback.