ci: remove container, install mpi from python wheel

[romanc]

Description

This is a follow-up from NOAA-GFDL/NDSL#184 (mpi4py >= 4.1), similar to NOAA-GFDL/pace#131, removing the mpi container in favor of installing a python wheel on the bare-metal Ubuntu runner. This allows the MPI tests in this testsuite to run again.

How Has This Been Tested?

By running CI and observing that "Orchestrated dace-cpu Acoustics" is now running again. Previously, that was just skipped.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas: N/A
• I have made corresponding changes to the documentation: N/A
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules
• New check tests, if applicable, are included: N/A (old ones are restored though ...)
• Targeted model if this changed was triggered by a model need/shortcoming: N/A