Use 'nwx_find_package' wrapper find MPI

[zachcran]

Description

This PR utilizes the find_package wrappers added by NWChemEx/NWXCMake#59 to find MPI's MPI::MPI_CXX target.

TODOs

• Verify that it works when built independently
• Verify that it works when built in Spack

[zachcran]

Checks can't pass until NWChemEx/NWXCMake#59 is merged.

[jwaldrop107]

LGTM

[zachcran]

@jwaldrop107 I'm not sure why the documentation build tests are failing, but this PR doesn't touch those. Any ideas? Otherwise, the test libraries are working now after the fix in NWChemEx/NWXCMake#60.

[ryanmrichard]

@jwaldrop107 I'm not sure why the documentation build tests are failing, but this PR doesn't touch those. Any ideas? Otherwise, the test libraries are working now after the fix in NWChemEx/NWXCMake#60.

Try changing the Sphinx requirement to version 8.1.

[zachcran]

Try changing the Sphinx requirement to version 8.1.

Do you mean to set something like sphinx>=8.1 or sphinx==8.1 in the requirements.txt file? (here)

Also, I can reproduce this error on my local system even with Sphinx==9.1.0.

[jwaldrop107]

@zachcran Issues over on sphinx_tabs imply that it's not currently compatible with Sphinx 9+, and the test is also running with 9.1. Restricting the sphinx version to 8.x may resolve the failure.

[zachcran]

@jwaldrop107 @ryanmrichard Looks like pinning the Sphinx version worked. Thanks! This is ready to go now, aside from the check that is stuck in queue purgatory (and already passed last time).