Issue verification for create-files has unexpected behavior

[amyschoen]

I'm not sure if this is something we want to fix or not, but it definitely behaving differently than it did previously. I sometimes test by reusing a class repo and cleaning up files created, removing collaborators, and closing all but the first class issue. It used to just generate new issues. At first, I thought that issue generation is still broken, but I saw that it updated one of the closed issues. Curious on if we should fix to only check currently open issues or if my testing use cases are strange enough that it doesn't make sense to add the filter.