[meld] CI: Add an explicit setuptools requirement

[Kai Willadsen <kaiw src gnome org>]

commit ad86a0f441f2526f60634fab60b8bbe95ddecfb0
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Feb 13 14:29:15 2021 +1000

    CI: Add an explicit setuptools requirement
    
    This should really be being pulled in by cx_Freeze, but for some reason
    it isn't.

 .gitlab-ci.yml | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 07d10314..f65d6568 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -56,6 +56,7 @@ pytest:
       mingw-w64-${env:MSYS2_ARCH}-python3-cx_Freeze
       mingw-w64-${env:MSYS2_ARCH}-python3-gobject
       mingw-w64-${env:MSYS2_ARCH}-python3-pytest
+      mingw-w64-${env:MSYS2_ARCH}-python3-setuptools
       mingw-w64-${env:MSYS2_ARCH}-gtksourceview4
       mingw-w64-${env:MSYS2_ARCH}-gsettings-desktop-schemas
       glib2-devel