Fix net test

[svenklemm]

Switch out postman-echo.com test endpoint for httpbin.org

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.93%. Comparing base (ea07da1) to head (8d87c3c).
Report is 79 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8277      +/-   ##
==========================================
- Coverage   82.18%   81.93%   -0.26%     
==========================================
  Files         257      257              
  Lines       48263    48219      -44     
  Branches    12174    12167       -7     
==========================================
- Hits        39667    39507     -160     
- Misses       3721     3900     +179     
+ Partials     4875     4812      -63     

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[mkindahl]

Would be better to have our own echo server spun up as part of the job, but this solves the immediate problem so approving.

[fabriziomello]

Would be better to have our own echo server spun up as part of the job, but this solves the immediate problem so approving.

Well this httpbin can be executed locally: https://github.com/postmanlabs/httpbin (but IMHO it can be material for a following PR)