[rmodels] UpdateModelAnimation() reviewed matrix-transpose, only once per bone

[Arrangemonk]

i updated UpdateModelAnimation to calculate the inverted bone matrix only once per bone instead of for every vertex

i measured time and its only twice as fast as before, so its not much of an improvement but still better than nothing

[raysan5]

@Arrangemonk thanks for the review!

[JeffM2501]

Was this PR tested on any kind of complex model?
I understand what it's trying to solve, but the bone weight check is in the wrong place and will early out incorrect.
This looks like it only iterates 4 bones per model, not 4 bones per vertex.

I would remove this PR until the questions are answered or the code is fixed.

[raysan5]

@Arrangemonk Please, could you check the questions from Jeff? We have some concerns about the correctness of this optimization...

[Arrangemonk]

@JeffM2501 @raysan5 , the tests with the robot model were misleading, im sorry for causing inconvenience, in the future im going to test my ideas thoroughly, before creating a pull request