Revert "fix: use non-legacy pdfjs version"

This reverts commit 334f525.

Author: staceybeard

src/js/directives/pdf-viewer.directive.js

@@ -9,7 +9,7 @@
  *         Refactored as a directive by Stacey Beard, Aug 2021 (pdf-viewer.directive.js).
  */
 // See: https://github.com/mozilla/pdf.js/tree/master/examples/webpack
-import * as pdfjsLib from 'pdfjs-dist/webpack.mjs';
+import * as pdfjsLib from '../../lib/pdfjs_legacy_webpack.mjs';
 
 (function () {
     'use strict';

src/lib/pdfjs_legacy_webpack.mjs

@@ -0,0 +1,14 @@
+// SPDX-FileCopyrightText: Copyright (C) 2024 Opal Health Informatics Group at the Research Institute of the McGill University Health Centre <john.kildea@mcgill.ca>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+import { GlobalWorkerOptions } from "pdfjs-dist/legacy/build/pdf.mjs";
+
+if (typeof window !== "undefined" && "Worker" in window) {
+  GlobalWorkerOptions.workerPort = new Worker(
+    new URL("pdfjs-dist/legacy/build/pdf.worker.mjs", import.meta.url),
+    { type: "module" }
+  );
+}
+
+export * from "pdfjs-dist/legacy/build/pdf.mjs";