FF142 Relnote Animation.commitStyles no longer requires fill (mdn#40611)

* FF142 Relnote Animation.commitStyles no longer requires fill

* Update files/en-us/mozilla/firefox/releases/142/index.md

Co-authored-by: Dipika Bhattacharya <dipika@foss-community.org>

---------

Co-authored-by: Dipika Bhattacharya <dipika@foss-community.org>

Author: hamishwillee

files/en-us/mozilla/firefox/releases/142/index.md

@@ -55,6 +55,7 @@ Firefox 142 is the current [Beta version of Firefox](https://www.firefox.com/en-
 #### DOM
 
 - The {{domxref("Selection.getComposedRanges()")}} method is now supported, allowing developers to accurately get selected text ranges across shadow DOM boundaries. In addition, the methods {{domxref("Selection.setBaseAndExtent()","setBaseAndExtent()")}}, {{domxref("Selection.collapse()","collapse()")}}, and {{domxref("Selection.extend()","extend()")}} of the {{domxref("Selection")}} interface have been modified to accept nodes inside a shadow root. ([Firefox bug 1903870](https://bugzil.la/1903870)).
+- The {{domxref("Animation.commitStyles()")}} method no longer requires [`fill`](/en-US/docs/Web/API/KeyframeEffect/KeyframeEffect#fill) to be set on an animation to commit the computed styles after the animation has finished. Note that until more browsers support this change, you should continue to set `fill`. ([Firefox bug 1973203](https://bugzil.la/1973203)).
 
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