It was pointed out that the notification added in #131406 was incorrect
as it added a notification for an intended area rather than the type
of change. This adds a ND_KEYFRAME_AUTO, set on auto keyframe change.
Timeline header already listens for all NC_ANIMATION and tags redraw.
Pull Request: https://projects.blender.org/blender/blender/pulls/131454
793c9a8984