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


const sandboxAMDName = "pdfjs-dist/build/pdf.sandbox";
  const sandboxOutputName = "pdf.sandbox.js";
  const scriptingPath = TMP_DIR + "pdf.scripting.js";
  
  const sandboxDefines = builder.merge(defines, {
    PDF_SCRIPTING_JS_SOURCE: fs.readFileSync(scriptingPath).toString(),
  });
  fs.unlinkSync(scriptingPath);
  const sandboxFileConfig = createWebpackConfig(
    sandboxDefines,
    {
      filename: sandboxOutputName,
      library: sandboxAMDName,
      libraryTarget: "umd",
      umdNamedDefine: true,
    },
    extraOptions
  );
  return gulp
    .src("./src/pdf.sandbox.js")
    .pipe(webpack2Stream(sandboxFileConfig))
    .pipe(replaceWebpackRequire())
    .pipe(replaceNonWebpackImport())
    .pipe(replaceJSRootName(sandboxAMDName, "pdfjsSandbox"));
}
function createWorkerBundle(defines) {