BUG: MacOS tests failing

[aburrell]

Describe the bug

The updated MacOS no longer works with the current CI set up

To Reproduce

Steps to reproduce the behavior:

1. Go to https://github.com/aburrell/apexpy/actions/runs/16837472598/job/47700382738?pr=156
2. See error

Expected behavior

Test should pass: needs a different version of gcc.

[jklenzing]

I started poking into this. Found a few things that have changed:

• MacOs13 has been deprecated.
• Updating gcc to version 15 runs fine for the macos-latest jobs.

Before changes: https://github.com/jklenzing/apexpy/actions/runs/21524146627
After changes: https://github.com/jklenzing/apexpy/actions/runs/21526127351

Not sure why the previous version fails. It looks like gcc 14 isn't recognizing the fortran compiler. Partial output, see logs above for full list of fortran compilers it can't find:

 ../meson.build:17:0: ERROR: Unknown compiler(s): [['gfortran'], ['flang-new'], ['flang'], ['nvfortran'], ['pgfortran'], ['ifort'], ['ifx'], ['g95']]
      The following exception(s) were encountered:
      Running `gfortran --help` gave "[Errno 2] No such file or directory: 'gfortran'"
      Running `gfortran --version` gave "[Errno 2] No such file or directory: 'gfortran'"
      Running `gfortran -V` gave "[Errno 2] No such file or directory: 'gfortran'"