Remove unneeded code for toggeling dockwidget visibility
QDockWidget::toggleViewAction::toggled is emitted when minimizing the application window on X11 (https://bugreports.qt.io/browse/QTBUG-48161 potentially related). This will cause the dockwidget to be hidden when minimizing the window.
We don't actually seem to need that connection, triggering the action (via shortcut or menu) seems to correctly show/hide the dockwidget without it