[rmodel] `root` transform not applied for gltf animations

[chriscamacho]

Raylib does not apply the root node transform as it should when animating

This can be easily seen if you load and animate the GLTF "cesium man" example gltf

If you apply the root transform it will be upright. This can be seen with none raylib code tutorials for skinned animation

if you load it into Raylib you will note that the figure is animated on its side.