gpu/pass.rs: Remove Iterator::collect<Vec<_>> usage from bind calls

[gustafla]

I disliked that trivial resource bind calls were performing memory allocations, so I changed the gpu API.

However, I want you to take a moment to discuss whether the API should have a newtype for *mut SDL_GPUBuffer that is used for a sys-crate bind-call, just like it has one for SDL_GPUBufferBinding and SDL_GPUTextureSamplerBinding.

In my opinion, there should be an opaque newtype for that, and the API shouldn't just use the raw pointer that can be obtained from Buffer::raw() and Texture::raw().

[gustafla]

Ah, I noticed @quaternic has created a refactoring PR for the whole API. Should we work together on this? I don't want any unnecessary memory allocations in my GPU API wrapper crate.

[gustafla]

I'm closing this for now in favor of #158