Glacian

I removed the old skybox implementation and I replaced it with a more simple one with a day night cycle. I also migrated the entire codebase from a workspace into a single crate so it is easier to navigate. I also migrated the crate to use vulkanalia instead of ash along with its sibling crate vulkanalia-vma instead of vk_mem. I did that since vulkanalia has a much more pleasant version of working with vulkan extensions (uses traits instead of duplicated instances). I also changed some nix stuff to use flakes (should hopefully make releases easier). I also did some cleanup removing old half finished stuff and removed WGPU support. This was never intended to run in the web browser and just using MoltenVK or KosmicKrisp on macOS is a lot simpler.