The `animrig::assign_action(action, id)` function now takes a `bAction` pointer (instead of its C++ wrapper `animrig::Action`). This makes it easier to call from code that just deals with the DNA/C struct. Also an override was added that takes an `OwnedAnimData` struct instead of just the ID. This saves the lookup of the AnimData, to be used in cases where the caller already has it. Pull Request: https://projects.blender.org/blender/blender/pulls/128030