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.

• asgiref changes from 3.11.1 to 3.12.1
• cffi changes from 2.0.0 to 2.1.0
• charset-normalizer changes from 3.4.7 to 3.4.9
• coverage[toml] changes from 7.15.0 to 7.15.2
• django changes from 5.2.15 to 5.2.16
• filelock changes from 3.29.5 to 3.31.0
• jaraco-functools changes from 4.5.0 to 4.6.0
• pip-tools changes from 7.5.3 to 7.6.0
• platformdirs changes from 4.10.0 to 4.10.1
• pylint-django changes from 2.7.0 to 2.8.0
• python-discovery changes from 1.4.3 to 1.4.4
• soupsieve changes from 2.8.4 to 2.9
• tomlkit changes from 0.15.0 to 0.15.1
• tox changes from 4.56.1 to 4.57.0
• tzdata changes from 2026.2 to 2026.3
• virtualenv changes from 21.5.1 to 21.6.1