Update macOS version in ci

[Algiane]

Update version for macos github runners before their deletion.

[Algiane]

Remark:

• passing fortran argument by reference using the %val keyword is not standard and seems to not be supported by gfortran-14 on arm architecture;
• initially, we choose to use this feature in order to have a Fortran-C interface allowing variadic functions (I didn't figure out how to do that using Iso-C binding when the interface was implemented a decade ago);
• a solution may be to rewrite the Fortran-C interface using Iso-C binding...
• another solution may be to pass pointers to the C variadic function if we come from a Frotran call and to dereference the pointer in C.