Doesn't look like the mac version was signed right, and gatekeeper is denying it. Would you be able to fix that?
Viewing post in Fast Forge jam comments
So it seems as though I there isn't anything I can do on my end without an official developer license or something of the sort. However I did find this page from the Godot documentation that shows ways you can try to run it anyways. If it's any help, I gave it a bundle identifier but had Notarization disabled on export.
Article: https://docs.godotengine.org/en/stable/tutorials/export/running_on_macos.html