Don't alter Item in code called from Item's destructor
QQuickItem::~QQuickItem calls setParentItem(null) before closing
This emits itemChange with ItemRemoved on the column view for that item
We then call ContentItem::forgetItem
And adjust the visibility.
This is problematic as we then start emitting all sorts of things after our item is being destroyed. Objects monitoring, in this case the attached accessiblity object can then do something that crash.
The only other caller of forgetItem is the removeItem method, so the setVisible call is moved there.
Tested by setting up orca Reproducing crash Testing fix