Some example artifacts don't link correctly on buildkite

## Describe the bug

Some artifacts from our examples suite don't link correctly on buildkite. See, for instance

https://buildkite.com/clima/climacore-ci/builds/1083#2e697241-9d82-40f5-8cc2-e2c82881dee8/133-152

or this one:

https://buildkite.com/clima/climacore-ci/builds/1083#e2f1f6d0-577b-4ce6-97e2-fc2322a27f0e/133-138

The artifacts are created and uploaded, but they are not being embedded in the log output.

## To Reproduce
To reproduce it is sufficient to check any buildkite log file. The culprit is that some examples have this to link the figures:

```julia
joinpath(@__DIR__, "../..")
```

which should point to three levels up instead of two. I think this is due to the fact that PR #600 changed the path by adding the `hybrid/plane`, `hybrid/box` and `hybrid/sphere` subdirectories but these were not updated in the call to the `linkfig` function.

Some other examples (e.g., `examples/hybrid/sphere/deformation_flow.jl` ) don't even have a specific call to `linkfig` though. So I wonder if it is needed at all.

## Related issues / PRs
#600

cc:
@dennisYatunin @simonbyrne