Skins are rendered wrong

[SpraxDev]

Describe the bug
The 2D Renderer has problems with skin overlays having an alpha of below 100% replacing the pixel underneath it instead of still showing the one below.

The 3D Renderer has a simillar problem, where rendering such overlay, not showing what's behind that pixel.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://api.sprax2013.de/mc/skin/x-url/body?url=https://cdn.skindb.net/skins/2258170679830512715 and https://api.sprax2013.de/mc/skin/x-url/body/3d?url=https://cdn.skindb.net/skins/2258170679830512715
2. 2D version has white (transparent) pixels around the goggles (less than 100% alpha, but fully replacing the pixel underneath it)
3. 3D version has a large transparent area around its neck that should not be there

[SpraxDev]

The cache might need some time to catch up again - But the fix is now live.