Document type child nodes not showing custom icons

[skttl]

Which Umbraco version are you using?

8.13.0

Bug summary

When using custom icons from /App_Plugins/*/backoffice/icons, they don't show up in the document type editor, when showing allowed child node types.

Specifics

No response

Steps to reproduce

Add some icons in App_Plugins/*/backoffice/icons, and select them on a doctype used as a child node for another document type.

Open the parent document type, and see the icon is missing on the child types.

Expected result / actual result

Expected the icon to show, just like the default icons does.

[bjarnef]

PR submitted: #10344 🔥

[nathanwoulfe]

Fixed in #10344