chore: simplify javascript example (#5050)

Author: caalador

articles/flow/component-internals/element-api/calling-javascript.adoc

@@ -83,8 +83,7 @@ public void complete() {
 [source,java]
 ----
 public void setItems(List<String> items) {
-    ArrayNode array = JacksonUtils.listToJson(items);
-    getElement().executeJs("this.items = $0", array);
+    getElement().executeJs("this.items = $0", items);
 }
 ----
 ====