Delete properties dialog on close

Fixes the game file being locked until Dolphin closes.

Source/Core/DolphinQt/GameList/GameList.cpp

@@ -431,6 +431,9 @@ void GameList::OpenProperties()
     return;
 
   PropertiesDialog* properties = new PropertiesDialog(this, *game);
+  // Since the properties dialog locks the game file, it's important to free it as soon as it's
+  // closed so that the file can be moved or deleted.
+  properties->setAttribute(Qt::WA_DeleteOnClose, true);
 
   connect(properties, &PropertiesDialog::OpenGeneralSettings, this, &GameList::OpenGeneralSettings);