bevy_image ktx2 reorders data instead of using wgpu `MipXLayerYFaceZ`

[atlv24]

theres a line in bevy_render/src/texture/gpu_image.rs

// TODO: Is this correct? Do we need to use `MipMajor` if it's a ktx2 file?

Its only correct because bevy_image manually reorders ktx2 data from MipXLayerYFaceZ to LayerYFaceZMipX. This is unnecessary and we should just use the wgpu enum for this.

[brianreavis]

A fix for this is included in #18411