The issue was that the `PointerRNA` passed to `BKE_animsys_get_nla_keyframing_context`
needs to point to an `ID` which wasn't the case when keying bones.
That is because internally the `FCurve` path is used to resolve the property.
This can only work from the `ID` because the `FCurve` path is always stored relative to that.
While the function doesn't fail when the property can't resolve the path, it won't actually do
the remapping when passing it to `BKE_animsys_nla_remap_keyframe_values` later.
Pull Request: https://projects.blender.org/blender/blender/pulls/120008
6276dd2f64