Attach (recommended) or Link to PDF file here:
See pdf in https://github.com/mozilla/pdf.js/issues/3109

Configuration:
- Web browser and its version: Firefox nightly
- Operating system and its version: Windows 10
- PDF.js version: builtin viewer

Steps to reproduce the problem:
1. Look at outlines

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/141514798-0e656865-1cbf-4fb8-a89b-530d36da23c9.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/141514740-c95e0237-8bf4-4129-a4a5-cb2ea5a3f4df.png)

const pageLabels = await pdfDocument.getPageLabels();
      expect(pageLabels).toEqual(null);
    });
    it("gets page labels", async function () {
      
      const loadingTask0 = getDocument(buildGetDocumentParams("bug793632.pdf"));
      const promise0 = loadingTask0.promise.then(function (pdfDoc) {
        return pdfDoc.getPageLabels();
      });
      
      const loadingTask1 = getDocument(buildGetDocumentParams("issue1453.pdf"));
      const promise1 = loadingTask1.promise.then(function (pdfDoc) {
        return pdfDoc.getPageLabels();
      });
      
      const loant(buildGetDocumentParams("rotation.pdf"));
      const promise2 = loadingTask2.promise.then(function (pdfDoc) {
        return pdfDoc.getPageLabels();
      });
      
      const loadingTask3 = getDocument(
        buildGetDocumentParams("bad-PageLabels.pdf")
      );
      const promise3 = loadingTask3.promise.then(function (pdfDoc) {
        return pdfDoc.getPageLabels();
      });
      const pageLabels = await Promise.all([
        promise0,
        promise1,
        promise2,