Fix GitHub CI workflow and Spack environment issues

[mingchen-NOAA]

Pull Request Summary

This PR resolves multiple issues causing failures in the WW3 GitHub CI workflows.

Description

This PR fixes several issues in the WW3 GitHub CI workflows:

1. Pins the Spack version used by the Intel workflow to provide a consistent and reproducible CI environment.
2. Updates the WW3 FTP regression-test input version to match the current regression tests.
3. Sets the Spack CPU target to x86_64_v3 for the GNU and Intel environments to prevent CPU architecture incompatibilities between GitHub runners and cached Spack dependencies.
4. Pins the Python version used by the Intel Spack environment to avoid the Python 3.13 build failure with the Intel classic compiler.

These changes are limited to the GitHub CI and Spack configurations. No WW3 source code or regression-test cases are modified.

Issue(s) addressed

fixes #1630

Commit Message

Fix GitHub CI workflow failures and Spack environment issues

Check list

• Branch is up to date with the authoritative repository (NOAA-EMC) develop branch.
• Checked the checklist for a developer submitting to develop.
• If a version number update is required, checked the updating version number checklist.
• If a new feature was added, a regression test for testing the new feature is added.

Testing

• How were these changes tested? Matrix
• Are the changes covered by regression tests? (If not, why? Do new tests need to be added?) Yes
• Have the matrix regression tests been run (if yes, please note HPC and compiler)? Hercules Intel
• Please indicate the expected changes in the regression test output, (Note the list of known non-identical tests.)
• Please provide the summary output of matrix.comp (matrix.Diff.txt, matrixCompFull.txt and matrixCompSummary.txt):

**********************************************************************
********************* non-identical cases ****************************
**********************************************************************
mww3_test_03/./work_PR1_MPI_d2                     (13 files differ)
mww3_test_03/./work_PR3_UNO_MPI_e_c                     (1 files differ)
mww3_test_03/./work_PR3_UQ_MPI_d2                     (17 files differ)
mww3_test_03/./work_PR2_UNO_MPI_d2                     (17 files differ)
mww3_test_03/./work_PR3_UNO_MPI_d2                     (18 files differ)
mww3_test_03/./work_PR2_UQ_MPI_d2                     (16 files differ)
mww3_test_03/./work_PR3_UQ_MPI_e                     (1 files differ)
mww3_test_03/./work_PR3_UQ_MPI_d2_c                     (15 files differ)
mww3_test_03/./work_PR2_UNO_MPI_e                     (1 files differ)
mww3_test_03/./work_PR3_UQ_MPI_e_c                     (1 files differ)
mww3_test_03/./work_PR3_UNO_MPI_e                     (1 files differ)
mww3_test_03/./work_PR2_UQ_MPI_e                     (1 files differ)
mww3_test_03/./work_PR1_MPI_e                     (1 files differ)
mww3_test_03/./work_PR3_UNO_MPI_d2_c                     (14 files differ)
mww3_test_09/./work_MPI_ASCII                     (0 files differ)
ww3_tp2.10/./work_MPI_OMPH                     (7 files differ)
ww3_tp2.16/./work_MPI_OMPH                     (4 files differ)
ww3_tp2.6/./work_ST4_ASCII                     (0 files differ)
ww3_ufs1.3/./work_a                     (2 files differ)

matrixCompFull.txt
matrixCompSummary.txt
matrixDiff.txt

[JessicaMeixner-NOAA]

Not running regression tests as this does not touch any code or the regtests and the CI tests passed.