MNT: Bump actions versions

[jhlegarreta]

Bump actions versions. Fixes:

Node.js 20 is deprecated. The following actions target Node.js 20 but
are being forced to run on Node.js 24: actions/checkout@v4,
actions/setup-python@v5. For more information see:
https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

raised for example in:
https://github.com/tee-ar-ex/trx-python/actions/runs/31469952202

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 63.57%. Comparing base (51efc18) to head (ffbf2ac).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #129   +/-   ##
=======================================
  Coverage   63.57%   63.57%           
=======================================
  Files          12       12           
  Lines        2570     2570           
=======================================
  Hits         1634     1634           
  Misses        936      936           

Flag	Coverage Δ
unittests	63.57% <ø> (ø)

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

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.