Fix CI issues

[mrakitin]

Some errors appear here: https://github.com/NSLS-II-SMI/smi-analysis/actions/runs/6471534300/job/17570166621:

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
=========================== short test summary info ============================
ERROR smi_analysis/SMI_test.py - ValueError: Expression 4.0e-9*π/λ*sin(arctan2(sqrt(x * x + y * y), z)/2.0) has forbidden control characters.
ERROR smi_analysis/tests/test_pygix_transform.py - ValueError: Expression 4.0e-9*π/λ*sin(arctan2(sqrt(x * x + y * y), z)/2.0) has forbidden control characters.