Attempting to upgrade RHV-H fails with error ("dnf.exceptions.Error: No packages marked for upgrade")

Issue

• When attempting to upgrade my RHV-H host via command line, I see the following error:

[root@host1 ~]# yum upgrade redhat-virtualization-host-image-update
Updating Subscription Management repositories.
Red Hat Virtualization Host for RHEL 8 x86_64 (RPMs)                             125 kB/s | 251 kB     00:02    
Last metadata expiration check: 0:00:01 ago on Tue 27 Apr 2021 20:39:00 AEST.
Package redhat-virtualization-host-image-update available, but not installed.
No match for argument: redhat-virtualization-host-image-update
Error: No packages marked for upgrade.

• When run with the debug option (-d10), we see:

Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/dnf/cli/main.py", line 67, in main
    return _main(base, args, cli_class, option_parser_class)
  File "/usr/lib/python3.6/site-packages/dnf/cli/main.py", line 106, in _main
    return cli_run(cli, base)
  File "/usr/lib/python3.6/site-packages/dnf/cli/main.py", line 122, in cli_run
    cli.run()
  File "/usr/lib/python3.6/site-packages/dnf/cli/cli.py", line 1162, in run
    return self.command.run()
  File "/usr/lib/python3.6/site-packages/dnf/cli/commands/upgrade.py", line 89, in run
    raise dnf.exceptions.Error(_('No packages marked for upgrade.'))
dnf.exceptions.Error: No packages marked for upgrade.
Error: No packages marked for upgrade.