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 IMAGE_DECODERS_DIR = BUILD_DIR + "image_decoders/";
const IMAGE_DECODERS_LEGACY_DIR = BUILD_DIR + "image_decoders-legacy/";
const DEFAULT_PREFERENCES_DIR = BUILD_DIR + "default_preferences/";
const MINIFIED_DIR = BUILD_DIR + "minified/";
const MINIFIED_LEGACY_DIR = BUILD_DIR + "minified-legacy/";
const JSDOC_BUILD_DIR = BUILD_DIR + "jsdoc/";
const GH_PAGES_DIR = BUILD_DIR + "gh-pages/";
const SRC_DIR = "src/";
const LIB_DIR = BUILD_DIR + "lib/";
const DIST_DIR = BUILD_DIR + "dist/";
const TYPES_DIR = BUILD_DIR + "types/";
const TMP_DIR = BUILD_DIR + "tmp/";
const TYPESTEST_DIR = BUILD_DIR + "typestest/";
const COMMON_WEB_FILES = [
  "web/images/*.{png,svg,gif}",
  "web/debugger.{css,js}",
];
const MOZCENTRAL_DIFF_FILE = "mozcentral.diff";
const REPO = "git@github.com:mozilla/pdf.js.git";
const DIST_REPO_URL = "https://github.com/mozilla/pdfjs-dist";
const builder = require("./external/builder/builder.js");
const CONFIG_FILE = "pdfjs.config";
const config = JSON.parse(fs.readFileSync(CONFIG_FILE).toString());
const ENV_TARGETS = [
  "last 2 versions",
  "Chrome >= 76",
  "Firefox ESR",
  "Safari >= 13.1",
  "> 1%",
  "not IE > 0",