ci: use upload-artifact v4 in integration tests

[Khoyo]

No description provided.

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 28.04%. Comparing base (5bf48e4) to head (4347bf5).

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@             Coverage Diff              @@
##                dev    #8099      +/-   ##
============================================
- Coverage     28.05%   28.04%   -0.01%     
  Complexity     2081     2081              
============================================
  Files          1289     1289              
  Lines        157727   157727              
  Branches       3114     3114              
============================================
- Hits          44251    44240      -11     
- Misses       111601   111612      +11     
  Partials       1875     1875              

Flag	Coverage Δ
core	75.19% <ø> (ø)
editoast	70.74% <ø> (-0.04%)	⬇️
front	9.90% <ø> (ø)
gateway	2.34% <ø> (ø)
railjson_generator	87.49% <ø> (ø)
tests	72.93% <ø> (ø)

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

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