Draft: Update Ironbank Docker tags

This MR contains the following updates:

Package	Update	Change
ironbank/nirmata/kyverno	patch	v1.5.7 -> v1.5.8
registry1.dso.mil/ironbank/nirmata/kyverno	patch	v1.5.7 -> v1.5.8
registry1.dso.mil/ironbank/nirmata/kyvernopre	patch	v1.5.7 -> v1.5.8
registry1.dso.mil/ironbank/opensource/kubernetes-1.21/kubectl	patch	v1.21.2 -> v1.21.5
registry1.dso.mil/ironbank/redhat/ubi/ubi8-minimal	minor	8.4 -> 8.5

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