test-write and test-xgc fail with recent version of adios

test-write and test-xgc both fail with same error when using a newer version of ADIOS. Error is

terminating with uncaught exception of type std::logic_error: ERROR: BeginStep() is called a second time without an intervening EndStep()

Test passes on CI where the ADIOS version is currently bf3a13d9f76983341de83c544a82f0bd58eb2ff8, which is around the 2.7 release. So some change in ADIOS since then is breaking the way we're doing the BeginStep() and EndStep() calls in Fides.