In Webpack 5, the [recommended way](https://webpack.js.org/guides/web-workers/) to create a web worker is

```ts
new Worker(new URL('./worker.js', import.meta.url));
```

Could we update\* the [`pdfjs-dist/webpack` entrypoint](https://github.com/mozilla/pdfjs-dist/blob/master/webpack.js) to use this syntax instead of the legacy `worker-loader`? One of the Webpack contributors told me that `worker-loader` uses "magic" and can cause issues.

\* To maintain compatibility with people still using Webpack 4, we should probably introduce a new entrypoint called `pdfjs-dist/webpack5` (or something like that) rather than changing the existing entrypoint.

Can attempt a PR if you would like.

Closely-related: https://github.com/mozilla/pdf.js/issues/15302


console.log();
  console.log("### Building default preferences");
  const bundleDefines = builder.merge(defines, {
    LIB: true,
    SKIP_BABEL: false,
    BUNDLE_VERSION: 0, 
    BUNDLE_BUILD: 0, 
    TESTING:
      defines.TESTING !== undefined
        ? defines.TESTING
        : process.env.TESTING === "true",
  });
  const inputStream = merge([
    gulp.src(["web/app_options.js"], {
      base: ".",
    }),
  ]);
  return buildLibHelper(
    bundleDefines,
    inputStream,
    DEFAULT_PREFERENCES_DIR + dir
  );
}
function getDefaultPreferences(dir) {