Fix numpy deprecation in an example

[sciunto]

Description

See https://scikit-image.org/docs/dev/auto_examples/color_exposure/plot_local_equalize.html#sphx-glr-auto-examples-color-exposure-plot-local-equalize-py

Checklist

• Docstrings for all functions
• Gallery example in ./doc/examples (new features only)
• Benchmark in ./benchmarks, if your changes aren't covered by an
  existing benchmark
• Unit tests
• Clean style in the spirit of PEP8

For reviewers

• Check that the PR title is short, concise, and will make sense 1 year
  later.
• Check that new functions are imported in corresponding __init__.py.
• Check that new features, API changes, and deprecations are mentioned in
  doc/release/release_dev.rst.

[grlee77]

Looks good, thanks!

[grlee77]

There are quite a few CI errors, but they look unrelated. It is a warning related to registration for colormaps within seaborn.

/opt/hostedtoolcache/Python/3.8.10/x64/lib/python3.8/site-packages/seaborn/cm.py:1582: UserWarning:

Trying to register the cmap 'rocket' which already exists.

/opt/hostedtoolcache/Python/3.8.10/x64/lib/python3.8/site-packages/seaborn/cm.py:1583: UserWarning:

Trying to register the cmap 'rocket_r' which already exists.

/opt/hostedtoolcache/Python/3.8.10/x64/lib/python3.8/site-packages/seaborn/cm.py:1582: UserWarning:

Trying to register the cmap 'mako' which already exists.

/opt/hostedtoolcache/Python/3.8.10/x64/lib/python3.8/site-packages/seaborn/cm.py:1583: UserWarning:

Trying to register the cmap 'mako_r' which already exists.

/opt/hostedtoolcache/Python/3.8.10/x64/lib/python3.8/site-packages/seaborn/cm.py:1582: UserWarning:

Trying to register the cmap 'icefire' which already exists.

/opt/hostedtoolcache/Python/3.8.10/x64/lib/python3.8/site-packages/seaborn/cm.py:1583: UserWarning:

Trying to register the cmap 'icefire_r' which already exists.

/opt/hostedtoolcache/Python/3.8.10/x64/lib/python3.8/site-packages/seaborn/cm.py:1582: UserWarning:

Trying to register the cmap 'vlag' which already exists.

/opt/hostedtoolcache/Python/3.8.10/x64/lib/python3.8/site-packages/seaborn/cm.py:1583: UserWarning:

Trying to register the cmap 'vlag_r' which already exists.

/opt/hostedtoolcache/Python/3.8.10/x64/lib/python3.8/site-packages/seaborn/cm.py:1582: UserWarning:

Trying to register the cmap 'flare' which already exists.

/opt/hostedtoolcache/Python/3.8.10/x64/lib/python3.8/site-packages/seaborn/cm.py:1583: UserWarning:

Trying to register the cmap 'flare_r' which already exists.

/opt/hostedtoolcache/Python/3.8.10/x64/lib/python3.8/site-packages/seaborn/cm.py:1582: UserWarning:

Trying to register the cmap 'crest' which already exists.

/opt/hostedtoolcache/Python/3.8.10/x64/lib/python3.8/site-packages/seaborn/cm.py:1583: UserWarning:

Trying to register the cmap 'crest_r' which already exists.

[grlee77]

actually, I am not sure the above warnings are the cause of the failure. It looks like it may have been:

Warning, treated as error:
/home/runner/work/scikit-image/scikit-image/skimage/viewer/viewers/core.py:docstring of skimage.viewer.viewers.core.CollectionViewer:1:duplicate object description of skimage.viewer.viewers.core.CollectionViewer, other instance in api/skimage.viewer, use :noindex: for one of them

but that is also unrelated to this PR