Bugfix when using pyet method to calculate PET

[shartgring]

Issue addressed

Fixes #907

Explanation

Use pyet.calc_ea instead of pyet.calc_e0 in PET workflow.

Note: The line pyet.calc_ea(tmax=temp_max, tmin=temp_min, rh=temp_dew) is still confusing as rh and temp_dew get mixed up (I got confused myself when submitting this PR, hence changing it to draft and back). However, the bug itself gets fixed and the changed code works without raising an error, contrary to the current code in main.

Checklist

• [x] Updated tests or added new tests
• [x] Branch is up to date with main
• [x] Tests & pre-commit hooks pass
• [x] Updated documentation if needed
• [ ] Updated changelog.rst if needed
• [x] For predefined catalogs: update the catalog version in the file itself, the references in data/predefined_catalogs.yml, and the changelog in data/changelog.rst

Additional Notes (optional)

Add any additional notes or information that may be helpful.