Add MPI environment variables for orion/hercules

[JessicaMeixner-NOAA]

What new functionality do you need?

Following the discussion here:
ufs-community/ufs-weather-model#2486
at the scalability meeting last week, it was decided that the MPI environment variables mentioned by @theurich should be included in the workflow.

I will add these.

What are the requirements for the new functionality?

Run c768/c1152 on orion/hercules w/new environment variable.

Acceptance Criteria

Run high res forecast on orion/hercules.

Suggest a solution (optional)

No response