GitFlow: Merge develop into main

[mathomp4]

NOTE: This is zero-diff for L72, but non-zero-diff for non-L72 runs.

NOTE 2: This should be taken with GEOSgcm_GridComp v3.0.1

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This pull request introduces a new diagnostic field for stable, cold-surface wind maximum (WSPD_STABLE300M), refines the workflow configuration for CI, and adds new subroutines for calculating horizontal temperature gradients. The changes enhance diagnostics for katabatic wind detection, improve code modularity, and update CI workflows to use the latest baseline libraries and fixture references.

Diagnostics and Physics Enhancements:

• Added a new exported field WSPD_STABLE300M to track the maximum wind speed in the lowest 300m above freezing, stable surfaces (potentially katabatic zones), including logic to detect surface inversions and zero out wind if no inversion is present. (DynCore_GridCompMod.F90) [1] [2]
• Added new subroutines fv_getGradT_2D and fv_getGradT_3D to compute the magnitude of horizontal temperature gradients, with robust handling of topography and undefined values, and exposed them as public interfaces. (FV_StateMod.F90) [1] [2]
• Registered the new fv_getGradT_2D function in the grid component module for use in diagnostics. (DynCore_GridCompMod.F90)

Workflow and CI Updates:

• Updated the baseline libraries version to v8.32.0 in .circleci/config.yml and removed use of the special feature/sdrabenh/gcm_v12 fixture branch, switching to mainline development and enabling mepodevelop. (.circleci/config.yml) [1] [2] [3]
• Updated GitHub Actions workflow to remove the fixture-ref override and enable load-fms, aligning with the new fixture and build system. (.github/workflows/workflow.yml) [1] [2]

Internal Refactoring and Preparation:

• Added and initialized additional variables and indices in Run and RunAddIncs subroutines to support the new diagnostics and maintain consistency in grid indexing. (DynCore_GridCompMod.F90) [1] [2] [3] [4]
• Moved the calculation of height above surface to immediately before its use, ensuring correct vertical coordinate handling. (DynCore_GridCompMod.F90) [1] [2]

These changes collectively improve the model's diagnostic capability for cold-surface wind events, streamline CI workflows, and enhance code maintainability.