How can I run "podman run" commands from inside of an unprivileged pod as a rootless user on OpenShift?

Issue

• We are using our own CI/CD pipeline, such as Jenkins, and wish to run a container within an OpenShift pod in order to build container images.
• Attempting to run rootless containers with podman run specifically within a pod on Red Hat OpenShift Container Platform 4 produces errors of various kinds when running, including but not limited to:
  • /usr/bin/slirp4netns failed: \"open(\\\"/dev/net/tun\\\"): No such file or director
  • Error: OCI runtime error: runc: runc create failed: rootless container requires user namespaces
  • Error: OCI runtime error: crun: newgidmap: gid range [0-65335) -> [1-65335) not allowed
  • sh: /home/jenkins/@tmp/durable-ffffff/jenkins-log.txt: Permission denied