Recently we upgraded to Gulp 4. However, the following things still need to be addressed in some way:

- If a task series is executed with an anonymous function inside it, we'll see `Starting '<anonymous>'` in the output, which isn't that great. We need to either suppress it or use named functions.
- If a task is private, it should be hidden in some way. For example, `gh-pages-prepare` is only used in the public `web` target and should not be used on its own, however currently it shows in the default `gulp` output since it's a regular task. Perhaps we should mark them with an underscore?
const scriptingAMDName = "pdfjs-dist/build/pdf.scripting";
  const scriptingOutputName = "pdf.scripting.js";
  const scriptingFileConfig = createWebpackConfig(
    defines,
    {
      filename: scriptingOutputName,
      library: scriptingAMDName,
      libraryTarget: "umd",
      umdNamedDefine: true,
    },
    extraOptions
  );
  return gulp
    .src("./src/pdf.scripting.js")
    .pipe(webpack2Stream(scriptingFileConfig))
    .pipe(replaceWebpackRequire())
    .pipe(
      replace(
        'root["' + scriptingAMDName + '"] = factory()',
        "root.pdfjsScripting = factory()"
      )
    );
}
function createSandboxExternal(defines) {