OCP 4.15 is scheduled for end-of-life in ~4 months. To stay ahead of supportability issues and avoid tech debt during the 1.6 maintenance cycle, we should move the cluster pools to a +1 newer OCP version now.

This task involves updating the cluster pool configurations used for CI jobs to a supported, newer version of OpenShift (e.g., 4.16 or whatever is currently GA and stable).