[libhandy] Non-fast-forward update to branch wip/exalm/oops

[Adrien Plazas <aplazas src gnome org>]

The branch 'wip/exalm/oops' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  aec62e9... carousel: Null-check tracker before shifting position

Commits added to the branch:

  29372b8... carousel-box: Don't animate child removal during destructio