cartopy Remove Google Group link

Rationale

The Google Group is not much used any more, and over in Iris we have been discussing retiring it (https://github.com/SciTools/iris/issues/3860). Do you have any objections to that? Iris have decided to use GitHub Discussions instead. Possibly Cartopy doesn't need anything to replace it as there seems to be quite a lot of Cartopy activity on StackOverflow.

Implications

One less place for users to ask questions, but also one less place that support people need to keep on top of.

Sep 14 '22 13:09 rcomer

It looks like google groups are also mentioned: https://github.com/SciTools/cartopy/blob/main/.github/SUPPORT.md so that may be worth updating at the same time?

Sep 14 '22 15:09 lbdreyer

Nice spot @lbdreyer! I have removed that link and also copied the gitter link from the README, as I assume they should be consistent.

Sep 14 '22 15:09 rcomer

That's fine with me.

Sep 14 '22 19:09 dopplershift

We should maybe point to the Matplotlib Discourse which has a Cartopy category: https://discourse.matplotlib.org/c/3rdparty/cartopy/19

Sep 14 '22 22:09 QuLogic

Since the scope of the 3rd Party section on Matplotlib's Discourse seems pretty similar to what was previously written for the Google Group, I just reused that text.

Sep 16 '22 08:09 rcomer

Hi @SciTools/cartopy-devs, is there any more I should do for this one? The Google Group has now been retired.

Oct 06 '22 18:10 rcomer