[gimp/wip/Jehan/fix-CI-again] gitlab-ci: fix Windows CI builds.

[Jehan <jehanp src gnome org>]

commit 51dacddab52de26f90f476d53400b21ee95816f3
Author: Jehan <jehan girinstud io>
Date:   Mon Apr 27 14:46:11 2020 +0200

    gitlab-ci: fix Windows CI builds.
    
    Seems that msys2 packages can sometimes be compressed as `.tar.zst`
    instead of `.tar.xz`. I updated crossroad to handle this case. It now
    requires the additional pypi `zstandard` package.

 .gitlab-ci.yml | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 78c0286c76..647a565e57 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -192,12 +192,14 @@ deps-win64:
         pkg-config
         python3-distutils
         python3-docutils
+        python3-pip
         rpm
     - apt-get install -y --reinstall ca-certificates
     - git clone --depth=${GIT_DEPTH} git://git.tuxfamily.org/gitroot/crossroad/crossroad.git
     - cd crossroad
     - ./setup.py install --prefix=`pwd`/../.local
     - cd ..
+    - pip3 install zstandard
   script:
     - export PATH="`pwd`/.local/bin:$PATH"
     - crossroad w64 gimp --run="build/windows/crossbuild-gitlab-ci/build-deps.sh"
@@ -276,12 +278,14 @@ deps-win32:
         pkg-config
         python3-distutils
         python3-docutils
+        python3-pip
         rpm
     - apt-get install -y --reinstall ca-certificates
     - git clone --depth=${GIT_DEPTH} git://git.tuxfamily.org/gitroot/crossroad/crossroad.git
     - cd crossroad
     - ./setup.py install --prefix=`pwd`/../.local
     - cd ..
+    - pip3 install zstandard
   script:
     - export PATH="`pwd`/.local/bin:$PATH"
     - crossroad w32 gimp --run="build/windows/crossbuild-gitlab-ci/build-deps.sh"