doc: fix some incorrect information about QQuickPopup::popupType

Since we ran out of time, we're not going to make out styles bind on
popupType for 6.8.

Remove the claim that we are.

Also mention that we might make that decision later on.

Pick-to: 6.8 6.8.0
Change-Id: Iad0b8dedff0b66e75adb5b80e6bbd5d087ae5d66
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

src/quicktemplates/qquickpopup.cpp

@@ -2934,11 +2934,10 @@ void QQuickPopup::resetBottomInset()
     well. And if the menu is a sub-menu inside another menu, the parent (or root) menu
     will decide the type.
 
-    The default value is style-dependent, and can change in future versions of Qt.
-    The \l {macOS Style}, for example, sets \c {Menu.popupType} to be \c Popup.Native, while
-    the \l{Imagine Style} uses \c Popup.Window (which is the default when the style doesn't
-    set a popup type). If you always want to use native menus for all styles on macOS, for
-    example, you can do:
+    The default value is usually \c Popup.Item, with some exceptions, mentioned above.
+    This might change in future versions of Qt, for certain styles and platforms that benefit
+    from using other popup types.
+    If you always want to use native menus for all styles on macOS, for example, you can do:
 
     \code
     Menu {