[cleanup] remove unused utils.DrySiteNote warning
[cleanup] remove unused utils.DrySiteNote warning

DrySiteNote was dropped with patch
https://gerrit.wikimedia.org/r/c/pywikibot/core/+/404159

It can be removed now.

Change-Id: Id0099302eaa621ca20f6126a67c6f457725d7a60

wikimedia/pywikibot-core,wikimedia/pywikibot-core