Coming https://github.com/openshift/must-gather/pull/263#issuecomment-967024141. The latest discussion in https://redhat-internal.slack.com/archives/CKJR6200N/p1713538917855119.

Extend the oc rsync code to limit the amount of files collected. Either to the latest one (or latest few). E.g. through new `--last=N` argument. With the goal to reduce the size of must-gather collected data.

Use case: have gather_insight to collect only the latest archives.

No documentation changes

QE: oc rsync pulls only the latest files (as configured).