`integrationtest` not compatible with newer version (3.11.7) of Python

[jcfreeman2]

Described in more detail in https://github.com/DUNE-DAQ/daq-release/wiki/Externals-Survey#nfdt_dev_241213_a9, long story short is that whereas we've been using Python 3.10.10 for some time now in the DUNE DAQ stack, if we update to Python 3.11.7 the integration tests break thanks to the importation of integrationtest.data_classes. Eric pointed out it would be nice to future proof the code, so this should be addressed. Note that there's a special test nightly which provides this newer Python to work with: NFDT_DEV_250113_A9.