Here's my trick (maintaining a 15K star github project that gets a lot of issues filed): stay friendly and supportive, but encourage them to create a PR to fix the issue themselves (usually with me giving some hints how to).

It instantly filters out the low effort "I want you to work for me for free" people.

My aim is to turn as people as possible into contributors. You'd be surprised how often, especially with a few hints, go "hmm.. I guess a PR wouldn't be too hard and it be nice to contribute". And quite a few of these end up being repeat contributors, since a second PR is way easier than the first.

It also sends a signal: there's a gazillion things that could be improved about this project. Unless there is a contributor that is willing to make a PR, it is likely not going to happen.

And I spend a larger percentage of my time doing code review, which (as the BDFL) is more effective use of my time anyway.