Update to Qt6

[sneakers-the-rat]

The current source is based on Qt 5.12 which was released in 2018 and has been long since EoL.

Need to upgrade to Qt6, which is relatively straightforward, if tedious: https://doc.qt.io/qt-6/portingguide.html

Running software with years outdated libraries is a security risk :(

[sneakers-the-rat]

Quoting here from #67 because i never did for some reason:

The Qt6 transition is really almost done on https://github.com/Aharoni-Lab/Miniscope-DAQ-QT-Software/tree/feature-repro-build , the last remaining thing is to fix the changes in TreeView from Qt5 vs TreeView from Qt6 in the TreeViewerJSON model, I just don't personally have time at the moment to handle it