Update actions/upload-artifact to v4

[Stoops-ML]

From the Publish to PyPi action:

Deprecation notice: v1, v2, and v3 of the artifact actions
The following artifacts were uploaded using a version of actions/upload-artifact that is scheduled for deprecation: "python-package-distributions".
Please update your workflow to use v4 of the artifact actions.
Learn more: https://github.blog/changelog/2024-04-16-deprecation-notice-v3-of-the-artifact-actions/

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.26%. Comparing base (3eda138) to head (1a7dd32).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #140   +/-   ##
=======================================
  Coverage   99.26%   99.26%           
=======================================
  Files          13       13           
  Lines         811      811           
=======================================
  Hits          805      805           
  Misses          6        6           

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