Drop default compression in CF Writer

[sfinkens]

Drop default compression in CF Writer and delegate this to the user (via encoding keyword argument or dataset attribute). This closes #2244. Also, update documentation to use the new compression keyword instead of zlib, which closes #2386 .

I played around a bit with different combinations of backend versions (netCDF4, libnetcdf, xarray) and noticed that the keyword choice also depends on the underlying libnetcdf. If libnetcdf<4.9.0 only zlib works and compression is silently ignored. This is the case in our CI environment whereeccodes currently requires libnetcdf-4.8.

In order to make users aware of that, I added a little section in the documentation and issued a user warning if the backend versions don't match.

Waiting for #2391 to fix flake8 errors.

• Tests added
• Fully documented

[djhoese]

Can't say I'm happy with the amount of version checks needed but that's not your/our fault. Too bad it isn't easier.

Thanks for fixing this up. I had a couple comments, but otherwise looks pretty good.

[codecov]

Codecov Report

Merging #2390 (d54accf) into main (5f2e3a1) will increase coverage by 0.02%.
The diff coverage is 98.93%.

@@            Coverage Diff             @@
##             main    #2390      +/-   ##
==========================================
+ Coverage   94.71%   94.73%   +0.02%     
==========================================
  Files         329      329              
  Lines       48739    48790      +51     
==========================================
+ Hits        46161    46223      +62     
+ Misses       2578     2567      -11     

Flag	Coverage Δ
behaviourtests	4.41% <0.00%> (+<0.01%)	⬆️
unittests	95.36% <98.93%> (+0.02%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
satpy/tests/writer_tests/test_cf.py	99.60% <98.70%> (-0.12%)	⬇️
satpy/writers/cf_writer.py	95.63% <100.00%> (+0.47%)	⬆️
satpy/resample.py	79.96% <0.00%> (+0.65%)	⬆️
satpy/_compat.py	69.38% <0.00%> (+4.08%)	⬆️
satpy/_config.py	95.55% <0.00%> (+4.44%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[coveralls]

Coverage: 95.326% (+0.007%) from 95.319% when pulling d54accf on sfinkens:cf-writer-encoding into 5f2e3a1 on pytroll:main.

[mraspaud]

LGTM