Tag to be used with the main branch of atlas/athena.
Update(s) since 2.1.38:
- Removed AtlasHIP from the repository;
* It is now superseeded by CMake's built-in HIP support in atlas/athena;
- Added ONNXRuntime to AthGenerationExternals;
- Updated GDB to version 16.1;
- Cleaned / updated the CMake version requirements and policy settings;
- Introduced / updated the following AtlasLCG modules: FindLhapdf.cmake, FindRecola.cmake, Findsympy.cmake;
- CheckerGccPlugin updates for GCC 15;
- VecGeom and VecCore patches for Clang 19.