diamond trimmed with netherite can be upgraided to netherite

When a diamond helmet is trimmed with netherite it can still be upgraided to netherite. When this happens, the netherite trimmed netherite helmet will still have the netherite trim.

 

To replicate:

open a world in 23W04a

get a diamond helmet and give it a trim using netherite

upgraide the helmet to netherite