chore: Upgrade Python requirements

[edx-requirements-bot]

Python requirements update. Please review the changelogs for the upgraded packages.

[edx-requirements-bot]

List of packages in the PR without any issue.

• certifi changes from 2026.1.4 to 2026.2.25
• filelock changes from 3.24.3 to 3.25.0
• isort changes from 8.0.0 to 8.0.1
• tox changes from 4.44.0 to 4.47.0

[edx-requirements-bot]

These Packages need manual review..

• [REMOVED] chardet (6.0.0.post1) removed from the requirements
• [NEW] python-discovery (1.1.0) added to the requirements
• [MAJOR] virtualenv changes from 20.38.0 to 21.1.0

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.13%. Comparing base (041de21) to head (c76d9ce).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #428   +/-   ##
=======================================
  Coverage   94.13%   94.13%           
=======================================
  Files          31       31           
  Lines        3068     3068           
  Branches      191      191           
=======================================
  Hits         2888     2888           
  Misses        155      155           
  Partials       25       25           

Flag	Coverage Δ
unittests	94.13% <ø> (ø)

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