CI/MNT: CI test suite is broken

Current Behavior

Run pytest -v \
============================= test session starts ==============================
platform linux -- Python 3.12.14, pytest-9.1.1, pluggy-1.6.0 -- /opt/hostedtoolcache/Python/3.12.14/x64/bin/python
cachedir: .pytest_cache
rootdir: /home/runner/work/hutch-python/hutch-python
configfile: pyproject.toml
plugins: timeout-2.4.0
collecting ... collected 100 items / 1 error

==================================== ERRORS ====================================
_______________ ERROR collecting hutch_python/tests/test_cli.py ________________
/opt/hostedtoolcache/Python/3.12.14/x64/lib/python3.12/site-packages/pluggy/_hooks.py:512: in __call__
    return self._hookexec(self.name, self._hookimpls.copy(), kwargs, firstresult)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/opt/hostedtoolcache/Python/3.12.14/x64/lib/python3.12/site-packages/pluggy/_manager.py:120: in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/opt/hostedtoolcache/Python/3.12.14/x64/lib/python3.12/site-packages/_pytest/python.py:250: in pytest_pycollect_makeitem
    return list(collector._genfunctions(name, obj))
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/opt/hostedtoolcache/Python/3.12.14/x64/lib/python3.12/site-packages/_pytest/python.py:476: in _genfunctions
    self.ihook.pytest_generate_tests.call_extra(methods, dict(metafunc=metafunc))
/opt/hostedtoolcache/Python/3.12.14/x64/lib/python3.12/site-packages/pluggy/_hooks.py:573: in call_extra
    return self._hookexec(self.name, hookimpls, kwargs, firstresult)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/opt/hostedtoolcache/Python/3.12.14/x64/lib/python3.12/site-packages/pluggy/_manager.py:120: in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/opt/hostedtoolcache/Python/3.12.14/x64/lib/python3.12/site-packages/_pytest/python.py:124: in pytest_generate_tests
    metafunc.parametrize(*marker.args, **marker.kwargs, _param_mark=marker)
/opt/hostedtoolcache/Python/3.12.14/x64/lib/python3.12/site-packages/_pytest/python.py:1316: in parametrize
    argnames, parametersets = ParameterSet._for_parametrize(
/opt/hostedtoolcache/Python/3.12.14/x64/lib/python3.12/site-packages/_pytest/mark/structures.py:217: in _for_parametrize
    if len(param.values) != len(argnames):
       ^^^^^^^^^^^^^^^^^
E   TypeError: object of type 'PosixPath' has no len()
=============================== warnings summary ===============================
hutch_python/utils.py:175
  /home/runner/work/hutch-python/hutch-python/hutch_python/utils.py:175: DeprecationWarning: the 'ALL' constant is deprecated, use the 'HRuleStyle' and 'VRuleStyle' enums instead
    table.hrules = prettytable.ALL

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
=========================== short test summary info ============================
ERROR hutch_python/tests/test_cli.py - TypeError: object of type 'PosixPath' has no len()
!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!
========================= 1 warning, 1 error in 4.67s ==========================

Start by running pytest -v and inspect the parametrization in hutch_python/tests/test_cli.py, along with the pytest configuration in pyproject.toml. Use the reported PosixPath collection error to guide the investigation. Done means test collection succeeds and the full suite passes.