WIP: Updates for spack-stack: gsibec, fms, pfunit

[mathomp4]

Work in Progress

Current Status

Build testing at NAS

I'll probably/definitely need help, advice, etc. from @climbfuji and @AlexanderRichert-NOAA on mistakes I surely made...

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Description

This PR has updates for spack-stack v2.1. It's mainly involved with:

1. Add pFUnit 4.15.0 ([INSTALL]: pfunit 4.15.0 #1840)
2. Add FMS 2025.03 ([INSTALL]: for spack-stack-2.0, update to fms@2025.03 #1547)
3. Add gsibec 1.4.0 ([INSTALL]: for spack-stack-2.1, update to gsibec@1.4.0 #1648)
4. Remove sp library (Remove sp library in spack-stack-1.9.0 --> spack-stack-2.1.0 #1330)

I've also added a new ifx testing stack/setup for NAS as well as my testing for NAS-TOSS5 (see #1905 and #1907 )

Dependencies

This has a dependency on a spack-packages update as well.

• waiting on WIP: Updates for spack-stack: gsibec, fms, pfunit spack-packages#40

Issues addressed

Closes #1840
Closes #1547
Closes #1648
Closes #1330

Applications affected

• FMS and any of its dependencies
• gsibec
• Many

Systems affected

All of them?

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
  • ...

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

[mathomp4]

Note to @climbfuji I'll resolve the conflicts once I get a complete build at NAS working. I just don't want to mess with my setup quite yet...