chore: add support for Python 3.12 and Django 5.2

[jignaciopm]

🧩 Summary

This PR updates the project dependencies by running make upgrade, aligning them with the latest compatible versions under Python 3.12.
It also updates the Django version constraint to support Django 5.2 while maintaining compatibility with Python ≥3.11 (lower versions are no longer supported).

🛠️ Changes

• Updated dependency constraints to:

  Django<6.0
  Python>=3.11,<3.12

• Executed make upgrade using Python 3.12 to regenerate dependency lock files (requirements/*.txt).
• Verified compatibility across all plugins within the eox-plugins project.

✅ Rationale

• This upgrade ensures that the project:
• Remains compatible with modern Python runtimes (3.11 and 3.12).
• Adopts Django 5.2 improvements and security updates.
• Aligns dependency versions across all eox-related plugins.
• Deprecates support for Python versions older than 3.11.

🔍 Verification

• Ran make test-python under Python 3.12 — all tests passing.
• Confirmed plugin compatibility with Django 5.2.
• Validated that no legacy dependencies required Python <3.11.

[jignaciopm]

I already checked, and all the workflows are updated to the last major version.

[Asespinel]

I tested in my main env and the xblock is showing without any issues: