See https://github.com/fortran-lang/fpm/actions/runs/4881173513/jobs/8709745595.
It looks like the shell returns platform=mingw64_nt-10.0-20348 which is not supported by the install_intel script.
I may be doing something wrong, but I don't see any changes in system shell or environment variables before the setup-fortran step. Thanks in advance for your help!