Deprecations from external packages, that will become errors soon (no, not the Neil Diamond song :rofl: )

[valeriupredoi]

So, since we now have a brand spanking new environment supporting Python=3.11 (cheers for merging my baby PR @bouweandela :beer: ), I took a closer look at the warnings we get from the CI tests, and I notice two potentially error-y deprecations, see test run -

• psyplot:

  ../../../../../usr/share/miniconda3/envs/esmvaltool/lib/python3.11/site-packages/psy_simple/colors.py:75
  ../../../../../usr/share/miniconda3/envs/esmvaltool/lib/python3.11/site-packages/psy_simple/colors.py:75
  /usr/share/miniconda3/envs/esmvaltool/lib/python3.11/site-packages/psy_simple/colors.py:75: MatplotlibDeprecationWarning: The get_cmap function was deprecated in Matplotlib 3.7 and will be removed two minor releases later. Use ``matplotlib.colormaps[name]`` or ``matplotlib.colormaps.get_cmap(obj)`` instead.
  [[1., 1., 1., 1.]], mpl_get_cmap('Reds')(_color_array), axis=0)

• esmpy:

  
  ../../../../../usr/share/miniconda3/envs/esmvaltool/lib/python3.11/site-packages/esmpy/__init__.py:106
  ../../../../../usr/share/miniconda3/envs/esmvaltool/lib/python3.11/site-packages/esmpy/__init__.py:106
  /usr/share/miniconda3/envs/esmvaltool/lib/python3.11/site-packages/esmpy/__init__.py:106: DeprecationWarning: Implicit None on return values is deprecated and will raise KeyErrors.
  __author__ = msg["Author"]

../../../../../usr/share/miniconda3/envs/esmvaltool/lib/python3.11/site-packages/esmpy/init.py:107 ../../../../../usr/share/miniconda3/envs/esmvaltool/lib/python3.11/site-packages/esmpy/init.py:107 /usr/share/miniconda3/envs/esmvaltool/lib/python3.11/site-packages/esmpy/init.py:107: DeprecationWarning: Implicit None on return values is deprecated and will raise KeyErrors. homepage = msg["Home-page"]

../../../../../usr/share/miniconda3/envs/esmvaltool/lib/python3.11/site-packages/esmpy/init.py:108 ../../../../../usr/share/miniconda3/envs/esmvaltool/lib/python3.11/site-packages/esmpy/init.py:108 /usr/share/miniconda3/envs/esmvaltool/lib/python3.11/site-packages/esmpy/init.py:108: DeprecationWarning: Implicit None on return values is deprecated and will raise KeyErrors. obsoletes = msg["obsoletes"]

@schlunma knowing Philip updates the psyplot package decently regularily I wouldn't worry too much, but, you know...just in case, might be a good idea to send him a nudge. About the esmpy warning, again, let's not go all guns blazing to them, but just to keep it in mind :nerd_face: 

[billsacks]

For the ESMPy issue, see https://github.com/esmf-org/esmf/issues/140 -- I'll try to address that.

[valeriupredoi]

cheers muchly @billsacks - sorry, I fired and forgot about this one :grin:

[ehogan]

@valeriupredoi I have just started seeing the __author__ = msg["Author"] issue in the new environment I just created for the release (I didn't see this problem at all using the first environment I created for the release). They both contain the same version of esmpy though 🤔

(old-env) % conda list esmpy
# packages in environment at /miniforge3/envs/old-env:
#
# Name                    Version                   Build  Channel
esmpy                     8.4.2              pyhc1e730c_4    conda-forge
(new-env) % conda list esmpy
# packages in environment at /miniforge3/envs/new-env:
#
# Name                    Version                   Build  Channel
esmpy                     8.4.2              pyhc1e730c_4    conda-forge

Any thoughts? 😕