Fix/source dist

[iainrussell]

Description

Fixes ecmwf/eccodes#372. The only change in behaviour that might not be expected is that now a developer who clones the eccodes-python repo and does pip install -e . will not get eccodeslib installed automatically - they will have to manually install it if they wish it to be there.

Contributor Declaration

By opening this pull request, I affirm the following:

• All authors agree to the Contributor License Agreement.
• The code follows the project's coding standards.
• I have performed self-review and added comments where needed.
• I have added or updated tests to verify that my changes are effective and functional.
• I have run all existing tests and confirmed they pass.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 30.01%. Comparing base (68cff89) to head (388632a).
⚠️ Report is 12 commits behind head on develop.

Files with missing lines	Patch %	Lines
setup.py	0.00%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #141      +/-   ##
===========================================
- Coverage    30.03%   30.01%   -0.02%     
===========================================
  Files           34       34              
  Lines         6177     6180       +3     
  Branches       742      743       +1     
===========================================
  Hits          1855     1855              
- Misses        4293     4296       +3     
  Partials        29       29              

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[iainrussell]

OK, @shahramn, I've tested the deployment of this (platform agnostic wheels) on https://test.pypi.org/project/eccodes/#files and it looks good to me. A 'normal' install will bring in eccodeslib, and a --no-binary install will not. Feel free to merge when you're happy to do so.