Skin packs in the development_skin_packs folder don't appear in-game

development_skin_packs folder doesn't work at all. If you put a skin pack here, it won't even show up in game. This was on all versions I remember (1.14.x-1.18.30).

Steps to Reproduce:

1. Download the attached skin pack
2. Extract it to C:\Users\YourUsername\AppData\Local\Packages\Microsoft.MinecraftWindows\LocalState\games\com.mojang\development_skin_packs
3. Open Minecraft
4. Open the Dressing Room and see if the skin pack shows up

Observed Results:
The skin pack does not show up.

Expected Results:
The skin pack should show up.