project management / issue tracker advice
Don't try to minimize the amount of open issues in your issue tracker! Issues are *contributions* from users, telling you about problems that you were not aware of yet - they're not pests to get rid of.
Closing issues without either solving them or a good(!) reason why they won't be fixed - for *any* reason, including stalebots - will just sour people on your project. They won't tell you that; they'll just stop showing up. And the issue still won't be fixed.
Instead, treat your issue tracker like a priority queue: accept that you're never going to get to zero, accept that some issues will remain open a long time because they are not urgent, and find a good way to order the list by your criteria of importance.
Work on things as time permits, in order of importance, communicate this to users, and establish a good rhythm of bugfixes that users are happy with even if *their* specific bug isn't fixed yet.
There are a lot more useful thoughts on this topic in this article: https://apenwarr.ca/log/20171213