ClimaCoreMakie fieldheatmap gives warning

[imreddyTeja]

Describe the bug

Usage of ClimaCoreMakie.fieldheatmap or ClimaCoreMakie.fieldheatmap! causes the warning

shading = false` is not valid. Use `Makie.automatic`, `NoShading`, `FastShading` or `MultiLightShading`. Defaulting to `NoShading`

To Reproduce

This can be reproduced by running lib/ClimaCoreMakie/test/runtests.jl
Ideally a minimal reproducible example:

# some code here

Or even better, add it as a unit test, and open pull request.

Project

If not using the `examples` project: ``` paste your Project.toml here. ``` ``` paste your Manifest.toml here. ```

System details

Any relevant system information:

• Julia version
• operating system
• modules loaded on cluster (module list)

Related issues / PRs

Please add any relevant links.