Installation from PyPI leads to errors when loading GRIB files

[schlunma]

Hi!

We recently started looking into reading GRIB files with ESMValTool, which works really nicely with iris-grib! Thanks for the great package 🚀

However, we had some trouble installing it properly.

Installation from conda-forge with mamba install iris-grib gives the following environment, which allows us to read GRIB files without any troubles:

# Name                    Version                   Build  Channel
iris-grib                 0.18.0             pyhd8ed1ab_0    conda-forge
eccodes                   2.32.0               h35c6de3_0    conda-forge
python-eccodes            1.6.1           py311h1f0f07a_1    conda-forge

However, the PyPI installation (pip install iris-grib) gives the following environment

# Name                    Version                   Build  Channel
iris-grib                 0.18.0                   pypi_0    pypi
eccodes-python            0.9.9                    pypi_0    pypi

which leads to the following error when attempting to load the same GRIB file as before:

RuntimeError: Could not load the ecCodes library!

This is most likely related to the usage of the deprecated eccodes-python package instead of the eccodes.

[valeriupredoi]

Many thanks @schlunma - I have opened #357 to fix this 🍺