Rename local variable

[T,ci] Enable MPI tests in the testrunner

See merge request ogs/ogs!5141

where PETScVector is incorrectly used as serial vector type.

and one comment change

added a warning to use it for creating local vectors.

Lars Bilke authored 4 months ago and Dmitri Naumov committed 3 months ago

Was part of `tests_mpi`-target which was never tested in CI.
Tests will probably fail.

[TRM] Tests for a bentonite material model (implemented in generalmod, used via MFront)

See merge request ogs/ogs!5083