[gimp] (4 commits) Non-fast-forward update to branch wip/Jehan/CI-Windows

[Jehan <jehanp src gnome org>]

The branch 'wip/Jehan/CI-Windows' 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:

  5fc8fdd... build, gitlab-ci: add a script to cross-build GIMP with Git
  bfe0c31... Temporarily get rid of all other stages.
  6ba451d... Trying to find the right package name without even having A
  6f16aa6... Trying back Salamandar image.
  b67ee31... What happens if I remove the package? Is it default?
  8ce9fc1... Add rst2man deps.
  419306a... Don't install as --user.
  12d4060... Trying to install mingw-w64-gcc (again).

Commits added to the branch:

  a6ffaea... Temporarily get rid of all other stages.
  451609a... build, gitlab-ci: add a script to cross-build GIMP with Git
  e95b20e... gitlab-ci: move to debian testing image as base.
  9803337... Move to Debian testing (TODO: will be rebased).