Python binding tests failing on CI

[aborgna-q]

pytket cannot find the tket2.ops module.

============================= test session starts ==============================
platform linux -- Python 3.11.9, pytest-8.2.1, pluggy-1.5.0
rootdir: /home/runner/work/tket2/tket2
configfile: pyproject.toml
plugins: cov-5.0.0, hypothesis-6.102.6
collected 15 items / 2 errors

==================================== ERRORS ====================================
________________ ERROR collecting tket2-py/test/test_circuit.py ________________
ImportError while importing test module '/home/runner/work/tket2/tket2/tket2-py/test/test_circuit.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
/opt/hostedtoolcache/Python/3.11.9/x64/lib/python3.11/importlib/__init__.py:1[26](https://github.com/CQCL/tket2/actions/runs/9248580011/job/25439096636#step:8:27): in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
tket2-py/test/test_circuit.py:9: in <module>
    from tket2.ops import Tk2Op
E   ModuleNotFoundError: No module named 'tket2.ops'
__________________ ERROR collecting tket2-py/test/test_ops.py __________________
ImportError while importing test module '/home/runner/work/tket2/tket2/tket2-py/test/test_ops.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
/opt/hostedtoolcache/Python/3.11.9/x64/lib/python3.11/importlib/__init__.py:126: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
tket2-py/test/test_ops.py:2: in <module>
    from tket2.ops import Tk2Op, Pauli
E   ModuleNotFoundError: No module named 'tket2.ops'
=========================== short test summary info ============================
ERROR tket2-py/test/test_circuit.py
ERROR tket2-py/test/test_ops.py
!!!!!!!!!!!!!!!!!!! Interrupted: 2 errors during collection !!!!!!!!!!!!!!!!!!!!
============================== 2 errors in 0.80s ===============================

https://github.com/CQCL/tket2/actions/runs/9248580011/job/25439096636#step:8:30