Raise ImportError when cairocffi cannot load cairo - #32400

… ERROR collecting lib/matplotlib/tests/test_backends_rendering.py …
lib/matplotlib/backends/backend_cairo.py:18: in <module>
    import cairo
E   ModuleNotFoundError: No module named 'cairo'

During handling of the above exception, another exception occurred:
lib/matplotlib/tests/test_backends_rendering.py:21: in <module>
    from matplotlib.backends.backend_cairo import RendererCairo, cairo
lib/matplotlib/backends/backend_cairo.py:24: in <module>
    import cairocffi as cairo
.venv/lib/python3.14/site-packages/cairocffi/__init__.py:60: in <module>
    cairo = dlopen(
.venv/lib/python3.14/site-packages/cairocffi/__init__.py:57: in dlopen
    raise OSError(error_message)  # pragma: no cover
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
E   OSError: no library called "cairo-2" was found
E   no library called "cairo" was found
E   no library called "libcairo-2" was found
E   cannot load library 'libcairo.so.2': dlopen(libcairo.so.2, 0x0002): tried:
'libcairo.so.2' (no such file),
'/System/Volumes/Preboot/Cryptexes/OSlibcairo.so.2' (no such file),
'/usr/lib/libcairo.so.2' (no such file, not in dyld cache),
'libcairo.so.2' (no such file).
Additionally, ctypes.util.find_library() did not manage to locate a library
called 'libcairo.so.2'