LibWeb: Add HTMLOrSVGElement.autofocus

Author: https://github.com/Lubrsi
Commit: 469ef22a22
Pull-request: https://github.com/SerenityOS/serenity/pull/15964
Reviewed-by: https://github.com/awesomekling

Userland/Libraries/LibWeb/HTML/HTMLElement.idl

@@ -33,5 +33,6 @@ HTMLElement includes HTMLOrSVGElement;
 interface mixin HTMLOrSVGElement {
     [SameObject] readonly attribute DOMStringMap dataset;
 
+    [CEReactions, Reflect] attribute boolean autofocus;
     [CEReactions] attribute long tabIndex;
 };