Remove mention of xarray-mongodb

[TomNicholas]

The xarray_mongodb project hasn't had a release in over a year, and may not be maintained at all. The link to it was added to our docs in 2020 (#683), but I don't think it warrants a mention in our docs here anymore.

[keewis]

pypi puts the last release in January, so it did see some activity lately, although there was a big gap of more than three years before that. I'm not sure if we need the special section in the I/O docs, or if it would be better to instead move this to the ecosystem page (a special I/O section, maybe?)

[TomNicholas]

Oh I was confused by the fact their docs say that 0.3.0 was released in Jan 2024 when it was actually Jan 2025.

We could move it to the ecosystem page sure, I just feel that this not widely used project (it has just 2 stars on github) befits an special mention in our user guide.

[keewis]

yeah, but I think the ecosystem page is a way of making things more visible, even for projects that are not widely used already, so I wouldn't mind keeping it there. I do agree that special mentions in the user guide is weird, though, especially when we don't do that for other projects.

@crusaderky, as the main author of that package: what do you think?

[crusaderky]

The date in the changelog is a typo. Apologies. I'll fix it right away.
I was unable to update the project for a long time due to a lack of ownership.
I have recently recovered full ownership and the project is fully maintained.

Although I'm not particularly interested in spending substantial amount of time in feature updates myself, I'm happy to provide code review and/or promote active contributors to reviewer roles.

[TomNicholas]

Thanks @crusaderky.

In that case let's just move the mention to the xarray-ecosystem page. That would tidy up the IO docs page whilst still mentioning the project. I'll edit this PR.

[max-sixty]

(+ props to @TomNicholas for raising the issue, it can be harder to remove things than add things)