Use actions for setting up gnu and intel fortran compilers

[danielhollas]

For intel compilers, we now waste a lot of time downloading and installing it each time. We should use setup-oneapi action and use its cache.
https://github.com/rscohn2/setup-oneapi

Similarly, we can simplify setup for GNU compilers with fortran-lang/setup-fortran action.

See example setup here:
https://github.com/fortuno-repos/fortuno/blob/main/.github/workflows/ci.yml

Idea from https://fortran-lang.discourse.group/t/which-compilers-are-available-for-ci-with-github-hosted-runners-all-but-nagfor/7554/4?u=daniel_hollas

[danielhollas]

Going to close this for now, we're using the setup-fortran action for ifx compiler. We can't switch GCC yet until we decide to drop support for GCC 7.