What to do with a forked repo after your PR has been accepted

If I do not have a reason to suspect I will contribute to it again withing a week, I just delete it.

I do not like my repo list to be cluttered with repos that I am not significantly involved with. The same goes for other people's repo lists when I review job candidates.

If you plan to continue contributing to a project, keep the fork. Otherwise, no point cluttering up your disk or your account.