With the Qt6 compatibility break, it can finally be removed.
Closing windows (which might quit the application with
quitOnLastWindowClosed() true, the default) acted contrary to the
documentation of the commitDataRequest() signal, which could have
been a hint.
This removes the workaround API from the fix for QTBUG-49667 and
also removes the problematic feature that it worked around.
Change-Id: I672be58864ef062df7fb7f2a81658b92c4feedd2
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
7f878c6217