Calling `Renderer::duplicate_object` and immediately dropping the original object keeps the original around for longer than expected

[nicx256]

As mentioned on Discord: https://discord.com/channels/451037457475960852/895788158938140702/1190185435805257748

The context is i'm trying to change the material on an object, and sometimes it appears as if the original object and the one with the updated material are clipping through each other: faces with both the new and updated materials are visible at once. This only happens rarely, but enough to notice if you aren't constantly redrawing frames as fast as possible