API returns 500 on sport calendar

[dantetemplar]

Describe the bug

api-1  |   File "/code/src/modules/ics/routes.py", line 157, in get_sport_current_user_schedule
api-1  |     ical_bytes = await get_personal_sport_ics(user)
api-1  |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
api-1  |   File "/code/src/modules/ics/utils.py", line 212, in get_personal_sport_ics
api-1  |     trainings = type_adapter.validate_python(response.json())
api-1  |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
api-1  |   File "/opt/pysetup/.venv/lib/python3.12/site-packages/pydantic/type_adapter.py", line 135, in wrapped
api-1  |     return func(self, *args, **kwargs)
api-1  |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^
api-1  |   File "/opt/pysetup/.venv/lib/python3.12/site-packages/pydantic/type_adapter.py", line 366, in validate_python
api-1  |     return self.validator.validate_python(object, strict=strict, from_attributes=from_attributes, context=context)
api-1  |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
api-1  | pydantic_core._pydantic_core.ValidationError: 1 validation error for list[Training]
api-1  | 110.extendedProps.training_class
api-1  |   Input should be a valid string [type=string_type, input_value=None, input_type=NoneType]
api-1  |     For further information visit https://errors.pydantic.dev/2.9/v/string_type

Reproduction

1. Open your dashboard and you will not see any sport check-in because of 500

Screenshots / Additional context

No response