The `TEST-UNEXPECTED-FAIL | checks that docIds are unique and increasing | in chrome | Expected 9 to be less than 0` unit test failed in a recent test run in https://github.com/mozilla/pdf.js/pull/13837#issuecomment-890511627, but also locally once for me. Perhaps this goes wrong because the test depends on state that might be mutated if the tests are shuffled?

/cc @Snuffleupagus since this unit test was added in https://github.com/mozilla/pdf.js/pull/13813/commits/b18620ac0f196c6fa5a9e54a53fa6b915e19e843
buildGetDocumentParams("Pages-tree-refs.pdf")
      );
      const page1 = loadingTask.promise.then(function (pdfDoc) {
        return pdfDoc.getPage(1).then(
          function (pdfPage) {
            expect(pdfPage instanceof PDFPageProxy).toEqual(true);
            expect(pdfPage.ref).toEqual({ num: 6, gen: 0 });
          },
          function (reason) {
            throw new Error("shall not fail for valid page");
          }
        );
      });
      const page2 = loadingTask.promise.then(function (pdfDoc) {
        return pdfDoc.getPage(2).then(
          function (pdfPage) {
            throw new Error("shall fail for invalid page");
          },
          function (reason) {
            expect(reason instanceof Error).toEqual(true);
            expect(reason.message).toEqual(
              "Pages tree contains circular reference."
            );
          }
        );
      });
      await Promise.all([page1, page2]);
      await loadingTask.destroy();
    });
    it("gets page index", async function () {