Fix "Render docs" CI job

[LewisGaul]

Hopefully fixing two issues that have started being hit in the "Render docs" CI job:

• podman pod create failing with "initializing source docker://k8s.gcr.io/pause:3.5: Requesting bear token: invalid status code from registry 404 (Not Found)", reported at add auto/light/dark mode for docs #625 (comment) and seen in other PRs too.
  • Fixed by updating podman in the CI, since doc generation involves running podman commands.
• ModuleNotFoundError: No module named 'griffe.collections' reported at add auto/light/dark mode for docs #625 (comment) and seen in other PRs too.
  • Fixed by updating doc package dependencies and pinning a couple more indirect dependencies (I think the lack of pinning griffe while pinning to an older version of mkdocstrings-python was the problem...).

[LewisGaul]

@gabrieldemarmiesse could you check the doc generation still works ok? I can't run it on my laptop since I don't have docker swarm set up. There are a bunch of warnings in the CI output about dead anchor links...

[gabrieldemarmiesse]

Thanks, I tested locally your branch (I usually disable the pods docs since I don't have podman locally) and it worked fine. Let's merge this. I still get a lot of warnings, which I believe we should fix at some point. Though it's not urgent.