Both `autokeyframe_object()` and `autokeyframe_pose_channel()` had an
odd structure where they would call completely different keying
functions depending on whether "Only Insert Available" was toggled on
or not. This not only overcomplicated the code, but also introduced
the possibility for divergent keyframing behavior depending on whether
that flag was set or not, beyond the intended effect of the flag.
This commit changes both functions to call the same keyframing function
(which already handles that flag correctly on its own) regardless of
whether that flag is set or not, unifying the keyframing behavior and
simplifying the code.
As a happy side effect, auto-keyframing failures are now reported even
when "Only Insert Available" is disabled, which wasn't the case before.
(An example of the aforementioned unintentional divergent behavior.)
Pull Request: https://projects.blender.org/blender/blender/pulls/121476