QmlDesigner: Fix state drop in same position

Avoid calling executeDrop() if the state is drop at the same index.

Task-number: QDS-7731
Change-Id: I91a2be11ce4f1c34c55ecb6dcc0c75f07114703a
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

share/qtcreator/qmldesigner/newstateseditor/Main.qml

@@ -639,6 +639,9 @@ Rectangle {
                                         return
                                     }
 
+                                    if (statesRepeater.grabIndex === stateThumbnail.visualIndex)
+                                        return
+
                                     statesRepeater.executeDrop(statesRepeater.grabIndex,
                                                                stateThumbnail.visualIndex)
                                 }