Description of problem:
6.12.5 upgrade fails due to dependency issue with rubygem-xmlrpc

Update package(s) : [31m[1m[FAIL][0m
Failed executing yum -y --disableplugin=foreman-protector update, exit status 1:
Updating Subscription Management repositories.
Red Hat Enterprise Linux 8 for x86_64 - BaseOS 32 MB/s | 62 MB 00:01
Red Hat Enterprise Linux 8 for x86_64 - AppStre 30 MB/s | 58 MB 00:01
Satellite 6.12 RHEL8 4.3 MB/s | 878 kB 00:00
Satellite Maintenance 6.12 RHEL8 163 kB/s | 7.6 kB 00:00
Error:
Problem: cannot install the best update candidate for package rubygem-xmlrpc-0.3.0-138.module+el8.6.0+16148+54b2ba8f.noarch

• nothing provides rubygem(webrick) needed by rubygem-xmlrpc-0.3.2-1.el8sat.noarch
  (try to add '-skip-broken' to skip uninstallable packages or '-nobest' to use not only best candidate packages)
  --------------------------------------------------------------------------------
  Scenario [Migration scripts to Satellite 6.12] failed.

The following steps ended up in failing state:

[packages-update]

Version-Release number of selected component (if applicable):
6.12.5

How reproducible:
100%

Steps to Reproduce:
1. Checkout the satellite base version of the 6.11.z
2. Prepare the setup for the 6.12.5 Snap 1 satellite upgrade.
3. Run the upgrade from 6.11.z to 6.12.5 Snap 1
4. Upgrade failed in the "Running Migration scripts to Satellite 6.12" stage

Actual results:
Upgrade fails at migration scripts

Expected results:
Upgrade runs successfully

Additional info:
This also fails for z stream upgrade (6.12.4 to 6.12.5)