fix: don't create empty .libs directory

[trim21]

close #488

only create ${package}.libs when needed

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.94%. Comparing base (e969b7b) to head (760b3f3).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #489      +/-   ##
==========================================
+ Coverage   91.87%   91.94%   +0.07%     
==========================================
  Files          20       20              
  Lines        1267     1266       -1     
  Branches      279      279              
==========================================
  Hits         1164     1164              
  Misses         57       57              
+ Partials       46       45       -1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[mayeut]

Thanks for your contribution, would you be able to add a test case for this as well (in tests/integration/test_manylinux.py:AnyLinux, the testsimple project can be used for the new test as it has no external dependency) ?