Add html_baseurl to sphinx conf.py

[jfrost-mo]

This is used to set the tag that points to the canonical version of the webpage. Including this indicates to search engines which version to include in their indexes, and should prevent older versions showing up.

Fixes #12363

It would be worth checking the ReadTheDocs admin settings first, which I don't have access to. But if the domain is already set correctly as the canonical one, then this PR should manually add in the required HTML tag.

This change will also have to be backported to old versions of the documentation to have the desired effect on search engine indexes.

[nicoddemus]

Thanks @jfrost-mo!

Here is the current configuration:

It would be worth checking the ReadTheDocs admin settings first, which I don't have access to. But if the domain is already set correctly as the canonical one, then this PR should manually add in the required HTML tag.

Is this correct?

[jfrost-mo]

In that case it looks like its not working for whatever reason. This PR is probably the way to go then, and it seems to work well enough.

Current docs:

With this PR:

[nicoddemus]

Great, thanks for confirming.

In any case, I personally prefer for that configuration to be in pytest's repository anyway, rather than "tucked away" in ReadTheDocs config.

Thanks again!

[jfrost-mo]

Once this is in it will need backporting to any branch that currently has published documentation to have its effect. Then you'll need to wait for the search engines to update their indexes, though this can be encouraged along by using the various search consoles to request a reindex: Google | Bing