add ubi8 and kubectl images to tests/images.txt
General MR
Summary
Adds images.txt to get the registry1.dso.mil/ironbank/redhat/ubi/ubi8-minimal:8.8
and registry1.dso.mil/ironbank/opensource/kubernetes/kubectl:1.27.5
images included in Kyverno's release images.txt
(Summarize the purpose of the MR)
Related to big-bang/bigbang#1801 (closed)
Relevant logs/screenshots
(Include any relevant logs/screenshots)
Edited by Tim Seagren