Update subscription-manager to 1.28.5-1
Resolves: #1886745 - Fix __init__ of CPProvider; ENT-3147 (jhnidek@redhat.com)
Resolves: #1833316 - unset-addons argument is missing in the bash completion of
Resolves: #1875595 - Service-Level set issues (wpoteat@redhat.com)