Always load 'mediawiki.special.changeslist' on appropriate pages

It is also loaded by ChangesList (and subclasses), but the changes
list might not get a chance to ever execute that code if there are no
changes to show.

This fixes an issue where the legend would sometimes display unstyled
on Special:RecentChangesLinked.

Bug: 59959
Change-Id: Ia1741306303aa3d2641b47bf19efef540ec64779