Support for Python > 3.8

The PDF library used to read timetables, [camelot-py](https://pypi.org/project/camelot-py), only supports Python versions 3.6, 3.7, and 3.8. Support for Python 3.10+ would be mandatory in a year since 3.8 will stop receiving security updates in Oct 2024.

Possible solutions:
- Use an alternate PDF library
- Fork and update the current library

Start by tracing the timetable-reading code that uses camelot-py and identify the dependency constraints preventing Python 3.10+. Compare the proposed alternate-library or fork approaches, then verify that timetable PDFs still parse correctly on Python 3.10 or newer.

Written by the indexing model from the issue text.