Description of problem:
When running leapp preupgrade checks on Workstation variants of RHEL 7, leapp does not report this as an inhibitor even though in-place upgrade of Workstation systems is not supported.

Version-Release number of selected component (if applicable):
leapp-0.15.0-2.el7_9.noarch

How reproducible:
Any time preupgrade report is created

Steps to Reproduce:
1. Install leapp on Workstation variant RHEL 7 system
2. Run leapp preupgrade.
3. Preupgrade does not note that the upgrade is unsupported on Workstation variant.

Actual results:
Leapp preupgrade does not report Workstation variant as an inhibitor.

Expected results:
Leapp preupgrade results should clearly report that an in-place upgrade of the system is unsupported and the only supported option is to install a fresh RHEL 8 system.