MSUnmerged: Roll back the change for filtering the slow RSEs from the list of cleaned sites.

[todor-ivanov]

Impact of the bug MSUnmerged

Describe the issue Due to the effects some slow sites have on the work of the rest of the service we had to filter out few of them in our configuration: https://github.com/dmwm/WMCore/issues/11839

The curren ticket is just a reminder to bring them back in, once we have them cleaned through some manual intervention in coordination with the site admins.

How to reproduce it Not needed

Expected behavior Not a bug

Additional context and error message N/A