Auto merge of #22347 - stevesweetney:master, r=ferjm

Implement HTMLMediaElement muted and defaultMuted attributes

<!-- Please describe your changes on the following line: -->
PR for issue  #22291

---
<!-- 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
- [X] These changes fix  #22291 (github issue number if applicable).
- [X] There are tests for these changes OR

<!-- 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/22347)
<!-- Reviewable:end -->

components/script/dom/webidls/HTMLMediaElement.webidl

@@ -55,8 +55,8 @@ interface HTMLMediaElement : HTMLElement {
   // controls
   // [CEReactions] attribute boolean controls;
   [Throws] attribute double volume;
-  // attribute boolean muted;
-  // [CEReactions] attribute boolean defaultMuted;
+  attribute boolean muted;
+  [CEReactions] attribute boolean defaultMuted;
 
   // tracks
   // readonly attribute AudioTrackList audioTracks;