[tests] Update tests

tests/classify/test_montgomery.py

tests/classify/test_tbx11k.py

tests/conftest.py

...data/histograms/models/histograms_lwnet_cxr8_default.json

...a/histograms/models/histograms_lwnet_drhagis_default.json

...ams/models/histograms_lwnet_drishtigs1_optic_cup_all.json

...histograms/models/histograms_lwnet_rimoner3_cup_exp1.json