Enable ADIOS2-based tests in pipepline

I recently recognised that, while we prepared the images for the pipeline jobs to include ADIOS2, the actual tests were not running, because HYTEG_BUILD_WITH_ADIOS2 had not been activated. This MR will change this. By default jobs will now build with ADIOS2. The only current exception is the clang_15_mpionly_petsc_trilinos in the pretest stage. IMHO at least one job should not include ADIOS2 to ensure we can build without this optional dependency.