Bug#1060318: silx: autopkgtest failure with Python 3.12

[PICCA Frederic-Emmanuel]

In order to reproduce the bug,

install python3-silx 2.0.0+dfsg-1

python3-pytest-xvfb pocl-opencl-icd

then

$ pytest --pyargs silx.image.test.test_medianfilter -v
=============================================================================================== test session starts ===============================================================================================
platform linux -- Python 3.11.8, pytest-8.0.2, pluggy-1.4.0 -- /usr/bin/python3
cachedir: .pytest_cache
rootdir: /home/picca/debian/science-team/pyvkfft
plugins: anyio-4.2.0, dials-data-2.4.0, xvfb-3.0.0
collected 2 items                                                                                                                                                                                                 

::TestMedianFilterEngines::testCppMedFilt2d PASSED                                                                                                                                                          [ 50%]
::TestMedianFilterEngines::testOpenCLMedFilt2d Abandon

the OpenCL test fails