Add example fpm package

[minhqdao]

This PR adds an example fpm package that is built and executed using the GitHub action.

• [x] Add example fpm package.
• [x] Fix missing dependencies on macOS.
• [x] Add workflow that manually installs dependencies.
• [x] Add workflow that uses awvwgk/setup-fortran@v1 to install dependencies.
• [x] Include ifx/ifort compilers.
• [x] Add cron job that runs once every month.

Jobs are here:

https://github.com/minhqdao/setup-fpm/actions/runs/5358956414 https://github.com/minhqdao/setup-fpm/actions/runs/5358956406

Closes https://github.com/fortran-lang/setup-fpm/issues/9 (I hope).

@everythingfunctional @LKedward @awvwgk