Update src/wp-includes/widgets/class-wp-widget-categories.php

Co-authored-by: Weston Ruter <[email protected]>

Author: joedolson

src/wp-includes/widgets/class-wp-widget-categories.php

@@ -119,7 +119,7 @@ function onCatChange(e) {
 	dropdown.addEventListener( 'click', function() {
 		dropdown.removeAttribute( 'data-lastkey' );
 	});
-	dropdown.onchange = onCatChange;
+	dropdown.addEventListener( 'change', onCatChange );
 })();
 </script>