7e4defbf3b
PR https://projects.blender.org/blender/blender/pulls/144233. Fix #142296 performance regression caused by merging UV positions based on face area weights, replacing it with mean average weights computation. The former method resulted in higher probability in making subdivision cache invalid between frame updates and thus causing expensive recreation of blender::bke::subdiv::OpenSubdiv_Evaluator object. While this fix isn't directly answering a question why specific UV position updates would cause this reevaluation of subdivision object, it fixes the performance regression caused by #139595 PR.