Update site configs for hercules / orion / ursa

[rickgrubin-noaa]

Description

Update site configs for hercules, orion, and ursa for release/2.1

• hercules
  • oneapi: use EPIC-installed compilers
  • gcc: update mpi external spec to address concretizer requirements
• orion
  • oneapi: use EPIC-installed compilers
• ursa
  • remove references to unnecessary paths / rpaths

Dependencies

None

Issues addressed

• Resolves Ursa: undefined reference in spack-stack/2.0.0 ecmwf-atlas-0.44.1 #1900
• Resolves Installation issue: py-scipy / spack-stack @ develop fails to configure with oneAPI @ 2024.2.1 on hercules and orion #1471 (already closed)

Applications affected

GDASapp, UFS-WM

Systems affected

• hercules
• orion
• ursa

Testing

• CI: Note whether the automatic tests (GitHub actions tests that run automatically for every commit) pass or not
  • GitHub actions CI tests pass
  • GitHub actions CI tests do not pass (provide explanation)
  • GitHub actions CI tests skipped (provide explanation if necessary)
• New tests added: List and describe any new tests added to GitHub actions
  • ...
• Additional testing: Add information on any additional tests conducted
  • GDASapp builds / successfully runs ctests (see Ursa: undefined reference in spack-stack/2.0.0 ecmwf-atlas-0.44.1 #1900)
  • UFS-WM builds with appropriate modulefile changes; not yet regression tested

Checklist

• This PR addresses one issue/problem/enhancement or has a very good reason for not doing so.
• These changes have been tested on the affected systems and applications.
• All dependency PRs/issues have been resolved and this PR can be merged.
• All necessary updates to the documentation (spack-stack wiki) will be made when this PR is merged

[climbfuji]

That looks great, much simpler!

[climbfuji]

I can merge this w/o testing after #1887

[RatkoVasic-NOAA]

LGTM