Add MPI as dependency

[jan-janssen]

Checklist

• [ ] Used a personal fork of the feedstock to propose changes
• [ ] Bumped the build number (if the version is unchanged)
• [ ] Reset the build number to 0 (if the version changed)
• [ ] Re-rendered with the latest conda-smithy (Use the phrase code>@<space/conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• [ ] Ensured the license file is being packaged.

[conda-forge-webservices[bot]]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipe:

• License is not an SPDX identifier (or a custom LicenseRef) nor an SPDX license expression.

Documentation on acceptable licenses can be found here.

[jan-janssen]

@conda-forge-admin, please rerender

[jan-janssen]

Traceback (most recent call last):
  File "/home/conda/feedstock_root/build_artifacts/mshr_1675392126330/test_tmp/run_test.py", line 2, in <module>
    import mshr
  File "/home/conda/feedstock_root/build_artifacts/mshr_1675392126330/_test_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_p/lib/python3.10/site-packages/mshr/__init__.py", line 24, in <module>
    from .cpp import Circle
ImportError: generic_type: type "CSGGeometry" referenced unknown base type "dolfin::Variable"

[jan-janssen]

It seems that with the switch from GCC 10 to 11 something changed in terms of the include paths.

[jan-janssen]

import: 'mshr'
--------------------------------------------------------------------------
The value of the MCA parameter "plm_rsh_agent" was set to a path
that could not be found:

  plm_rsh_agent: ssh : rsh

Please either unset the parameter, or check that the path is correct
--------------------------------------------------------------------------