Fixing CI for two touching cubes

[shimwell]

No description provided.

[shimwell]

@ebknudsen I have been trying to track down why one of the tests models (two touching cubes) fails and I think I've found the reason

before this last commit 799ab20 the test two_touching_cuboids cad-to-dagmc was failing.

the commit temporarily removed cad-to-openmc and after the commit on this PR branch the test then started working again.

So I think the [OCP or gmsh line] brings in a different version of open cascade (https://github.com/openmsr/CAD_to_OpenMC/blob/dfe6923b0cee5821588011e1feefefe96d49e469/requirements.txt#L6C1-L6C4) brought in the cad-to-openmc causes the - Exception: OpenCASCADE exception GeomAdaptor_Surface::UContinuity to occur when running cad-to-dagmc.

Now I think I know what is happening I can simply have two environments one for cad-to-openmc and one for cad-to-dagmc as it looks like they need slightly different versions of packages.

[shimwell]

PR #35 created to make a separate action for each convertor