This fix slightly changes the Voodoo Cursed Pyro Soul so that it reduces clipping with cosmetics that are intended to replace Pyro's head.

The original Voodoo Cursed Pyro Soul cosmetic includes a damaged gas mask revealing a skull underneath it. However, because the gas mask and skull are part of the cosmetic itself, it displays even if you equip an item that would normally hide Pyro's gas mask.

This change puts the damaged gas mask & skull on a new bodygroup option of Pyro's base model, and removes it from the Voodoo Cursed Pyro Soul itself.
With adjustments to the item schema entry for it on Valve's end, this should fix most major clipping issues with this cosmetic.

As an alternative, the modified SMD file for the Voodoo Cursed Pyro Soul could be implemented as a secondary style which just "enables" the default Pyro head bodygroup. Thus, any secondary cosmetics that would hide it would effectively accomplish the same thing without sacrificing loadouts where people deliberately utilize the clipping.

For reference, the Purity Fist for Heavy works similarly -- the Purity Fist is an "invisible cosmetic" and is tied to Heavy's model itself so that glove-related cosmetics (which should hide his default fists) don't clip.