excerpt from: leapp-upgrade.log
===============================
Error: Transaction test error:
  file /usr/share/redhat-logos from install of rocky-logos-90.14-1.el9.x86_64 conflicts with file from package rocky-logos-86.3-1.el
8.x86_64
===============================
but unlike other package conflicts (like make-devel), this package cannot be erased (need plymouth on boot)

[root@localhost leapp]# yum erase rocky-logos
Dependencies resolved.
====================================================================================================================================
 Package                                             Architecture   Version                                   Repository       Size
====================================================================================================================================
Removing:
 rocky-logos                                         x86_64         86.3-1.el8                                @System         366 k
Removing dependent packages:
 anaconda-gui                                        x86_64         33.16.8.9-1.el8_8.rocky.0.1               @System         2.4 M
 gdm                                                 x86_64         1:40.0-27.el8                             @System         4.9 M
 gnome-classic-session                               noarch         3.32.1-34.el8_8                           @System         195 k
 gnome-initial-setup                                 x86_64         3.28.0-11.el8                             @System         2.0 M
 gnome-session                                       x86_64         3.28.1-20.el8_8                           @System         1.5 M
 gnome-session-wayland-session                       x86_64         3.28.1-20.el8_8                           @System         2.4 k
 gnome-session-xsession                              x86_64         3.28.1-20.el8_8                           @System          11 k
"hack.txt" 51L, 4574C written
[root@localhost leapp]#