Make tests run again

.coverage

.coverage.DESKTOP-ATMEKSV.12160.XuMTRtDx

.coverage.DESKTOP-ATMEKSV.12392.XcvrcPpx

.coverage.DESKTOP-ATMEKSV.21188.XiwAGrAx

.coverage.DESKTOP-ATMEKSV.24596.XgBqmGkx

examples/analytical-function/example_analytical_function.py

examples/analytical-function/test_analytical_function.py

examples/umbridge_tsunamitutorial/example_umbridge.py

...es/umbridge_tsunamitutorial/example_umbridge_testmodel.py

src/bayesvalidrox/bayes_inference/discrepancy.py

src/bayesvalidrox/surrogate_models/engine.py

tests/test_Discrepancy.py

tests/test_ExpDesign.py