DOC: Update matplotlib intersphinx URL

[pllim]

Goes with astropy/astropy#12705 to address astropy/astropy#12698 . Also see astropy/regions#392 .

@dhomeier , I cannot add you as "reviewer" but please review. Thanks!

[dhomeier]

I've built the Astropy docs (without astropy/astropy#12705) against this and verified that the links are working without redirection, thanks!

[pllim]

Do you need a new release?

[pllim]

astropy/astropy#12705 is for consistency's sake, so would be nice if you could give that a quick review as well. Thanks!

[dhomeier]

Do you need a new release?

Not sure, currently regions does not set a minver for this at all – @larrybradley , would there also be a way to use the dev version for the doc builds?

[larrybradley]

@dhomeier I could update the tox build_docs environment, but that would only help for local doc builds. regions CI uses the RTD PR builder. Not sure if I can pin to a dev version for RTD. If this broken, then why not do a new release?

[pllim]

I could do a release. Just want to make sure there are no other stuff we need to fix beforehand.

[pllim]

If I don't hear back that I should wait in like 15 minutes, I'll cut a release. 😉

[pllim]

v1.7.0 is on PyPI now with this patch. Please let me know if you still have problems. Thanks for the reviews!