Add missing sourceElement to NavigateEventInit

This was missed in d5c8e5c. Fixes #10970.

Author: AtkinsSJ

source

@@ -95410,6 +95410,7 @@ dictionary <dfn dictionary>NavigateEventInit</dfn> : <span>EventInit</span> {
   DOMString? <dfn dict-member for="NavigateEventInit" data-x="dom-NavigateEventInit-downloadRequest">downloadRequest</dfn> = null;
   any <dfn dict-member for="NavigateEventInit" data-x="dom-NavigateEventInit-info">info</dfn>;
   boolean <dfn dict-member for="NavigateEventInit" data-x="dom-NavigateEventInit-hasUAVisualTransition">hasUAVisualTransition</dfn> = false;
+  Element? <dfn dict-member for="NavigateEventInit" data-x="dom-NavigateEventInit-sourceElement">sourceElement</dfn> = null;
 };
 
 dictionary <dfn dictionary>NavigationInterceptOptions</dfn> {