Auto merge of #18146 - cbrewster:insertadjacenthtml_cereactions, r=jdm

Annotate insertAdjacentHTML with CEReactions

<!-- Please describe your changes on the following line: -->

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

<!-- Either: -->
- [X] There are tests for these changes OR
- [ ] These changes do not require tests because _____

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

<!-- 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/18146)
<!-- Reviewable:end -->

components/script/dom/webidls/Element.webidl

@@ -77,7 +77,7 @@ interface Element : Node {
   Element? insertAdjacentElement(DOMString where_, Element element); // historical
   [Throws]
   void insertAdjacentText(DOMString where_, DOMString data);
-  [Throws]
+  [CEReactions, Throws]
   void insertAdjacentHTML(DOMString position, DOMString html);
 };
 

tests/wpt/metadata/custom-elements/reactions/Element.html.ini

@@ -6,9 +6,3 @@
   [slot on Element must enqueue an attributeChanged reaction when replacing an existing attribute]
     expected: FAIL
 
-  [insertAdjacentHTML on Element must enqueue a connected reaction for a newly constructed custom element]
-    expected: FAIL
-
-  [insertAdjacentHTML on Element must enqueue a attributeChanged reaction for a newly constructed custom element]
-    expected: FAIL
-