[gtk] (6 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:

  9a716c1... gdk: Introduce GdkColor
  f34ff5b... gsk: Add color space in gsk_renderer_render_texture
  94fe720... wip: update testsuite for changed compositing
  cf1917f... wip: Add a cicp color space implementation
  9568834... Add a quick-and-dirty heif loading test
  4f03f6d... widget-factory: Add an hdr image example

Commits added to the branch:

  146c91f... gdk: Introduce GdkColor
  242b582... gsk: Add color space in gsk_renderer_render_texture
  14c3e3b... wip: update testsuite for changed compositing
  e46e48c... wip: Add a cicp color space implementation
  a1e4eb8... Add a quick-and-dirty heif loading test
  15a29fd... widget-factory: Add an hdr image example