Shader passthrough alternative

[molikto]

Objective

Enable wgpu spirv-shader-passthrough.

Solution

if has wgpu::Features::SPIRV_SHADER_PASSTHROUGH, always load spirv shaders using the pass through. This is kind of a abuse of wgpu API, but I like it because the change is minimal to bevy, and it doesn't add extra features to bevy. I think this is a sensible default, and I don't want to build elaborate features without people actually finding this sensible default undesirable

alternative to #3996