[gimp-help] Remove two unused images

[Jacob Boerema <jboerema src gnome org>]

commit 626a915796238ece0b0acd9e6b25ecb0da79dc66
Author: Jacob Boerema <jgboerema gmail com>
Date:   Sun Mar 13 15:40:31 2022 -0400

    Remove two unused images
    
    There are a few more orphaned images, but they are all related to
    layer modes. The layer modes documentation is incomplete. We
    may need them again in the future for documenting the legacy
    layer modes. So, let's leave those for now.
    
    (cherry picked from commit d7f673eab6d08d90d5b6d8a52869b3ad83b5a247)

 images/C/dialogs/stock-floating-selection-16.png | Bin 712 -> 0 bytes
 images/C/toolbox/toolbox-icons.png               | Bin 12432 -> 0 bytes
 2 files changed, 0 insertions(+), 0 deletions(-)