Cannot start the editor after loading the demo data

The problem is that the path is given as a Path object, which is passed as is to QSettings (for saving the recent files list) and in the status.
The prevents the editor from even starting. This is a consequence of larray-project/larray#978 in larray 0.34 (but that PR is not buggy, the editor had just to be updated accordingly), so should not be mentioned in the changelog.