message: gltfpack: Fix processing for files with clearcoat textures
  Roughness/normal texture wasn't participating in the usesTextureSet
  function which meant that we could discard UV channels if they were
  *only* used by these maps - which might be uncommon but does happen in
  examples from glTF-Sample-Models.
diff: @@ -318,6 +318,12 @@ bool usesTextureSet(const cgltf_material& material, int set)
  {
  if (usesTextureSet(material.clearcoat.clearcoat_texture, set))
  return true;
  +
  + if (usesTextureSet(material.clearcoat.clearcoat_roughness_texture, set))
  + return true;
  +
  + if (usesTextureSet(material.clearcoat.clearcoat_normal_texture, set))
  + return true;
  }
  if (material.has_transmission)
  