Intermittent failure in /html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin-fragment.html #20768

  ▶ Unexpected subtest result in /html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin-fragment.html:
  │ FAIL [expected PASS] Tests that a fragment navigation in the unload handler will not block the initial navigation
  │   → assert_equals: expected "" but got "#fragment"
  │ 
  │ window.onload</window.finishedLoading<@http://web-platform.test:8000/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin-fragment.html:24:9
  │ Test.prototype.step@http://web-platform.test:8000/resources/testharness.js:1490:20
  │ Test.prototype.step_func_done/<@http://web-platform.test:8000/resources/testharness.js:1530:17
  └ @http://web-platform.test:8000/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin-fragment-2.html#fragment:7:5