refactor(ci/tests): use awvwgk/setup-fortran, use pytest tempdirs

[wpbonelli]

• switch to awvwgk/setup-fortran to install Intel compilers
  • temporarily set SETVARS_COMPLETED and CXX manually until action patched
• use pytest temp dir fixtures in autotests
• add pytest-dependency to test dep group in pyproject.toml
• add dependency marker to autotest/pytest.ini to avoid warnings

[codecov[bot]]

Codecov Report

Merging #136 (6ea01d1) into master (8f804f9) will decrease coverage by 4.371%. The diff coverage is n/a.

:exclamation: Current head 6ea01d1 differs from pull request most recent head 57063ea. Consider uploading reports for the commit 57063ea to get more accurate results

@@              Coverage Diff              @@
##            master      #136       +/-   ##
=============================================
- Coverage   73.513%   69.143%   -4.371%     
=============================================
  Files           20        20               
  Lines         3432      3432               
=============================================
- Hits          2523      2373      -150     
- Misses         909      1059      +150     

see 7 files with indirect coverage changes