DOC: remove incorrect colorbar reference from contours_topomap docstring

[deveshbervar]

Fixes #12698

What was changed

Removed the incorrect reference to the non-existent colorbar argument
from the contours parameter description in mne.viz.plot_topomap().

Why this change

The docstring mentioned colorbar=True, but plot_topomap() does not
have a colorbar argument. This PR updates the documentation to remove
the incorrect reference.

Implementation

• Updated docdict["contours_topomap"] in mne/utils/docs.py
• Removed the sentence referring to colorbar=True

[deveshbervar]

Hi @cbrnr, I noticed the CI checks are blocked due to the block-unregistered-user restriction. Could you please approve the workflow so the checks can run? Thanks!

[cbrnr]

I don't know why I can't re-run the CircleCI jobs. @larsoner can you help? I'm logged in with my account but the options are still grayed out. Do you need to add me to an org?

[tsbinns]

@deveshbervar If you link your GitHub account to CircleCI and push a commit (even an empty one), the docs build will run without us needing to manually approve it.

[deveshbervar]

Thanks! I’ve applied the suggested formatting fix.