[MAINT, MRG] Fix nilearn intersphinx

[alexrockhill]

Fixes warning causing CIs to fail in #10824.

[alexrockhill]

I was editing the wrong configuration file in the main mne module and not in docs this should fix it now.

[alexrockhill]

It looks like this fixed the warning but nilearn's intersphinx obj is timing out... It was doing that intermittently locally.

[alexrockhill]

Turns out it wasn't intermittent, they just moved to a stable/latest structure.

[drammock]

rather than ignoring the warning, it would be better to fix this upstream. See, e.g.

• MAINT: Docutils deprecation mcmtroffaes/sphinxcontrib-bibtex#302
• Use node.findall if available (docutils 18.x) numpy/numpydoc#403

for examples

[alexrockhill]

Huh the job was abandoned at 98% complete. Okay, @drammock, I'm removing the warning filters and I'll write a PR over there.

[alexrockhill]

This should be good to merge, it will fix one thing going wrong with the CIs today at least.

[larsoner]

Thanks @alexrockhill