Update useEffect to use new, consistent API

Author: SebastianAigner

src/jsMain/kotlin/App.kt

@@ -9,7 +9,7 @@ private val scope = MainScope()
 val App = functionalComponent<RProps> { _ ->
     val (shoppingList, setShoppingList) = useState(emptyList<ShoppingListItem>())
 
-    useEffect(dependencies = listOf()) {
+    useEffect {
         scope.launch {
             setShoppingList(getShoppingList())
         }