As we're adding tests for texture component swizzle in gpuweb/cts#4421 (comment), we wonder if we should "just" disallow swizzle with depth textures.

This issue tracks results so that we can bring them to the group.

EDIT(KN):

1. Disallow with depth textures always?
2. Disallow for depth bindings but allow for depth textures bound to unfilterable-float bindings? (see Should we raise an error if swizzle is used with sampleType: "depth" binding point? #5265)
3. Allow always?