[gtk] (3 commits) Non-fast-forward update to branch matthiasc/color-profile-rebased

[Matthias Clasen <matthiasc src gnome org>]

The branch 'matthiasc/color-profile-rebased' 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:

  5271a1a... Add libheif to the build
  b5a88b5... Add a quick-and-dirty heif loading test
  1619ec3... widget-factory: Add an hdr image example

Commits added to the branch:

  e6382c6... Add libheif to the build
  e874617... Add a quick-and-dirty heif loading test
  e1f43e7... widget-factory: Add an hdr image example