When doing connectivity checks of the host defined in the release image, and the installation is disconnected (as determined by the presence of registries.conf), the mirrors defined in registries.conf should also be checked. The check should confirm that at least mirror is reachable for each upstream source defined in this file.

See also:
https://redhat-internal.slack.com/archives/C02TGJZHW81/p1677053482437209

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