I think this is the clearest, easiest, correct answer. If you no longer have the time and motivation to maintain a project, and are also not in a position to hand over control to someone you have good reason to trust, the easy, safe answer is to retire it, and have others fork.

Then in the original project you can say “the last version of this project is N.N; here are some possible candidate successor forks, which have not been vetted”.

This way no one who is merely keeping up with version numbers will accidentally step off of a reasonably good package on to a fraudulent package.