Having a hard cut in the binning breaks for high occupancy

[ricmperes]

For high occupancy (center tiles) the gain/occupancy are still calculated with the area spectrum constrained to 0,20000 integrADCcounts. This biases the measured occ. and gives wrong gains at very high ilumination.

https://github.com/ricmperes/PyLArS/blob/de9dfd3946daf54e774a4d99fe83bfb8e85ffc53/pylars/analysis/ledwindow.py#L110C29-L110C66