Dependabot isn’t the only source of vulnerability fatigue, there are plenty of “researchers” who would spam your active projects about pointless “vulnerabilities”. For instance, I recently got one about a parsing issue in gmp from a human user, who probably found it by scanning PyPI. I’m not touching anything adjacent to the supposedly vulnerable codepath, and the fix isn’t even in a gmp release, meaning I would have to carry a patch if I were to “fix” it. I still responded amicably, but I was not happy.
There’s not really anything that can be done about that, yet, unfortunately. But if you’re not committing to the repo anymore, archiving it is an option. It’ll disable the issue tracker and pull request features. And if you change your mind, you can unarchive it.