PETSc Example Int64 CI

[jeremylt]

We can now use the PETSC_ARCH=mpich-hip-int64 in CI. @jrwrigh we probably don't need to run every fluids test in int64. Do you have a minimal subset you'd like to see? (we should probably trim out some of the GPU runs too since that's the bulk of our CI time) If you have a list of test cases that should be run, I can gen up a PR. Its easiest if the tests don't involve any file IO