Explicitly use popupType: Popup.Item in tst_qquickapplicationwindow

The test focusAfterPopupClosed(), checks to see that the delivery agent
causes correct updates to which item has active focus in a given scene.
However, when using popup windows, a popup's popupItem is moved into a
different scene, and the delivery agent won't respond the same.

We already have tests in tst_qquickpopup, to verify similar behavior
with popup windows.

Set the value to be explicitly Popup.Item, in case we change the default
value in the future.

Task-number: QTBUG-126553
Pick-to: 6.8
Change-Id: Ie1b2319adafc2b1a616d6b153fee49ac472a972c
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

tests/auto/quickcontrols/qquickapplicationwindow/data/focusAfterPopupClosed.qml

@@ -27,6 +27,7 @@ ApplicationWindow {
             Menu {
                 id: fileMenu
                 y: parent.height
+                popupType: Popup.Item
 
                 MenuItem {
                     text: qsTr("New")
@@ -52,6 +53,7 @@ ApplicationWindow {
     Popup {
         id: focusPopup
         focus: true
+        popupType: Popup.Item
         width: parent.width
         height: parent.height