Update 2 remaining unittests

[mo-tgeddes]

2 unittests are still failing in ants core:

• lib/ants/tests/fileformats/test_integration.py::TestExceptions::test_no_datum_warning
• lib/ants/tests/utils/test_transform_bbox.py::TestDiffCS::test_point_lie_beyond_crs_definition

These will need to be fixed/updated/removed as appropriate