Bug#917985: OpenFOAM should not build (nor skip) dummy libraries

The "dummy" library files are a useful part of the OpenFOAM build process. They are essentially stub libraries that can act as a failsafe for library interfaces that are unsupported or not available on the system. Additionally, the dummy Pstream is an extremely useful MPI stub. It obviously can

Bug#918112: openfoam should not massively pollute /usr/{bin,lib} namespaces

The merge request https://salsa.debian.org/science-team/openfoam/-/merge_requests/4 should solve these concerns.