Adjust release-tools code to use three versions for patch releases
Based on the current patch release workload, plus a decision to investigate upgrade needs more thoroughly, the maintenance policy extension is paused (details on #2947 (closed)). As part of &968 (closed), the patch release process was adjusted to use the new process but still left the required logic implemented in release-tools to create patch releases for the last three versions.
Once the maintenance policy extension is officially restarted, the logic introduced should be reconnected allowing patch releases for three versions to be created.