function removeExtension(gltf, extension) {
  removeExtensionsUsed(gltf, extension); // Also removes from extensionsRequired

  if (extension === "CESIUM_RTC") {
    removeCesiumRTC(gltf);
  }

  return removeExtensionAndTraverse(gltf, extension);
}
Removes an extension from gltf.extensions, gltf.extensionsUsed, gltf.extensionsRequired, and any other objects in the glTF if it is present.

@param {object} gltf A javascript object containing a glTF asset.
@param {string} extension The extension to remove.

@returns {*} The extension data removed from gltf.extensions.