I think these tags should definitely be merged. issue-tracker and support-tracker to me seem to mean the same thing. If one of the tags were, say, bug-tracker then I could see how it would relate to code; however, just the word, "issue" really doesn't apply only to code but could mean any issue. Referencing Wikipedia,
An issue tracking system (also ITS, trouble ticket system, support ticket, request management or incident ticket system) is a computer software package that manages and maintains lists of issues, as needed by an organization.
It seems that support ticket and issue tracker are the same, and I'm sure you could link support-tracker
with support ticket
as well.
I also agree with making issue-tracker the target as it has more questions associated with it and, from what I understand, it is more well known than support-tracker.