Reenable PSP due to RKE2 issues

NOTE: https://github.com/rancher/rke2/issues/2156

Nightly CI failing to come alive due to Gatekeeper pods being blocked by the default PSPs on RKE2 - https://repo1.dso.mil/platform-one/big-bang/bigbang/-/jobs/9982279

Given a good chunk of the customer base uses RKE2 I think the risk of disabling this at this point outweighs the gain. PSPs are deprecated in 1.22 but will not be removed until 1.25, which should give plenty of time for that RKE2 issue to be closed and us to test against distros.

Opened https://repo1.dso.mil/platform-one/big-bang/apps/core/policy/-/issues/153 to tackle disabling these again in the future...