Enable iscsi test

I have found that nested virtualization does not work for
other arches than x86, so the test is disabled for those
arches in the kola testiso code
We can re-enable this so it runs on x86 at least in the meantime

Tracker issue: coreos/fedora-coreos-tracker#1657

kola-denylist.yaml

@@ -11,8 +11,6 @@
   warn: true
   platforms:
     - azure
-- pattern: iso-offline-install-iscsi.bios
-  tracker: https://github.com/coreos/fedora-coreos-tracker/issues/1638
 - pattern: ext.config.files.console-config
   tracker: https://github.com/coreos/fedora-coreos-tracker/issues/1654
   streams: