Auto merge of #22149 - CYBAI:rejectionhandled, r=jdm

Implement rejectionhandled event

---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #22006 .
- [x] There are more tests `PASS`ed for these changes

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/22149)
<!-- Reviewable:end -->

tests/wpt/metadata/MANIFEST.json

@@ -625710,7 +625710,7 @@
    "testharness"
   ],
   "html/webappapis/scripting/processing-model-2/unhandled-promise-rejections/promise-rejection-events-onerror.html": [
-   "c76d531c43ec3ecc8cbf3c21f3a0ffa4db7be715",
+   "b6f6d63e0aa9660909c93e7366f80f4f36c97ecf",
    "testharness"
   ],
   "html/webappapis/scripting/processing-model-2/unhandled-promise-rejections/promise-rejection-events.dedicatedworker.html": [

tests/wpt/metadata/html/webappapis/scripting/processing-model-2/unhandled-promise-rejections/promise-rejection-events-onerror.html.ini

@@ -1,6 +0,0 @@
-[promise-rejection-events-onerror.html]
-  type: testharness
-  expected: TIMEOUT
-  [Throwing inside an unhandledrejection handler invokes the error handler.]
-    expected: TIMEOUT
-

tests/wpt/metadata/html/webappapis/scripting/processing-model-2/unhandled-promise-rejections/promise-rejection-events.html.ini

@@ -1,6 +0,0 @@
-[promise-rejection-events.html]
-  type: testharness
-  expected: TIMEOUT
-  [rejectionhandled is dispatched from a queued task, and not immediately]
-    expected: TIMEOUT
-

tests/wpt/web-platform-tests/html/webappapis/scripting/processing-model-2/unhandled-promise-rejections/promise-rejection-events-onerror.html

@@ -15,7 +15,7 @@ async_test(function(t) {
 
   window.onerror = function (msg, url, line, col, error) {
     t.step(function() {
-      assert_equals(msg, 'Uncaught Error: e2');
+      assert_true(msg.includes('e2'));
       assert_equals(error, e2);
     });
     t.done();