petab_sciml ModuleNotFoundError with non-SciML problems

[dweindl]

E.g. https://github.com/ICB-DCM/pyPESTO/actions/runs/31707062925/job/94470170005

  File "/home/runner/work/pyPESTO/pyPESTO/.tox/petab/lib/python3.12/site-packages/petab/v2/lint.py", line 576, in run
    required = get_required_parameters_for_parameter_table(problem)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/pyPESTO/pyPESTO/.tox/petab/lib/python3.12/site-packages/petab/v2/lint.py", line 1130, in get_required_parameters_for_parameter_table
    from .extensions.sciml_lint import get_nn_entity_petab_ids
  File "/home/runner/work/pyPESTO/pyPESTO/.tox/petab/lib/python3.12/site-packages/petab/v2/extensions/sciml_lint.py", line 7, in <module>
    from petab_sciml import (
ModuleNotFoundError: No module named 'petab_sciml'

PR in preparation.