Specification unclear on weather rendering into 3D textures is allowed

https://gpuweb.github.io/gpuweb/#abstract-opdef-gpurenderpasscolorattachment-gpurenderpasscolorattachment-valid-usage and https://gpuweb.github.io/gpuweb/#abstract-opdef-gpurenderpassdepthstencilattachment-gpurenderpassdepthstencilattachment-valid-usage should make clear that views into 3D textures are not allowed.