Global `callout-icon` parameter not working

[mthomas-ketchbrook]

When I add callout-icon: false to my _quarto.yml project file and render the document, I am still seeing icons in the callout blocks.

https://quarto.org/docs/authoring/callouts.html#icons

[mthomas-ketchbrook]

I haven't checked to see if either of the following work / do not work:

1. Setting #| callout-icon: false at the chunk-level
2. Setting callout-icon: false in the YAML header of the .qmd file itself