[DOC] Fix broken doc build

[ymzayek]

See error on main https://github.com/nilearn/nilearn/actions/runs/5071173662/jobs/9107231460

[github-actions]

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[codecov]

Codecov Report

Merging #3744 (11305a5) into main (6085633) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #3744   +/-   ##
=======================================
  Coverage   91.57%   91.57%           
=======================================
  Files         139      139           
  Lines       16572    16572           
  Branches     3236     3236           
=======================================
  Hits        15175    15175           
  Misses       1394     1394           
  Partials        3        3           

Impacted Files	Coverage Δ
nilearn/plotting/img_plotting.py	94.52% <ø> (ø)

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[ymzayek]

Merging this to green the dev doc build. The other failures are unrelated