Delete .github/workflows/add-issue-to-project.yml (#599)

> With respect to the failing CI, I recommend removing that workflow and using GitHub Projects's native way of automatically adding issues to projects. That can be done in a separate PR though.

I think @kanej added it. I'm happy to remove it if you don't think it is useful anymore?

_Originally posted by @OmarTawfik in #598 (comment)