Previously used MGXS_TYPES[:-1] but to be explicit, I instead looped over all MGXS_TYPES and excluded current.
These tests cannot run with current because:
-distribcell is not a valid domain for current
-nuclide/no_nuclides option is not relevant for current
These tests had to skip 'current' because current operates only with a mesh domain.
However, these tests impose a material domain. Therefore, they should not be run with current.
