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?
fs.unlinkSync(dir + "/web/debugger.js");
  fs.unlinkSync(dir + "/build/pdf.js");
  fs.unlinkSync(dir + "/build/pdf.worker.js");
  fs.unlinkSync(dir + "/build/pdf.sandbox.js");
  fs.renameSync(dir + "/build/pdf.min.js", dir + "/build/pdf.js");
  fs.renameSync(dir + "/build/pdf.worker.min.js", dir + "/build/pdf.worker.js");
  fs.renameSync(
    dir + "/build/pdf.sandbox.min.js",
    dir + "/build/pdf.sandbox.js"
  );
  fs.renameSync(
    dir + "/image_decoders/pdf.image_decoders.min.js",
    dir + "/image_decoders/pdf.image_decoders.js"
  );
}
gulp.task(
  "minified",
  gulp.series("minified-pre", async function (done) {
    await parseMinified(MINIFIED_DIR);
    done();
  })
);
gulp.task(
  "minified-legacy",
  gulp.series("minified-legacy-pre", async function (done) {
    await parseMinified(MINIFIED_LEGACY_DIR);
    done();
  })
);
function preprocessDefaultPreferences(content) {