Blender crashes when calling the python render operator when GPU
compositor execution is enabled. This is due to a missing system GPU
context, which is not initialized for blocking rendering. So this patch
ensures the system GPU context before compositing. Additionally, it
removes the assert that ensures a non main thread execution, since the
assumption apparently does not really hold.
Pull Request: https://projects.blender.org/blender/blender/pulls/122176
6ae98e43a9