Summary:
WebGPU: Textures should be able to have OUTPUT_ATTACHEMENT | SAMPLED usage flags.

All real GPU workloads will have multiple passes in order to render a scene. Most of this passes (except for the final on-screen pass) will happen in the intermediate render targets. An intermediate render target is both a texture that you render to and a texture that you sample from.

This is necessary for just about every rendering technique: Shadow maps, tone mapping, bloom, etc…