CI: move the package list to the config.yml file

Using templates for our CI is a bit of overkill but while we have it,
let's make use of it.

.gitlab-ci.yml

@@ -32,7 +32,7 @@ variables:
   # See the documentation here:                                                 #
   # https://wayland.freedesktop.org/libinput/doc/latest/building_libinput.html  #
   ###############################################################################
-  FEDORA_PACKAGES:    'git diffutils gcc gcc-c++ pkgconf-pkg-config meson systemd-devel protobuf-c-devel libxkbcommon-devel doxygen python3-attrs python3-pytest python3-dbusmock'
+  FEDORA_PACAKGES: 'git diffutils gcc gcc-c++ pkgconf-pkg-config meson systemd-devel protobuf-c-devel libxkbcommon-devel doxygen python3-attrs python3-pytest python3-dbusmock '
   ############################ end of package lists #############################
 
   # these tags should be updated each time the list of packages is updated

.gitlab-ci/ci.template

@@ -38,7 +38,9 @@ variables:
   # See the documentation here:                                                 #
   # https://wayland.freedesktop.org/libinput/doc/latest/building_libinput.html  #
   ###############################################################################
-  FEDORA_PACKAGES:    'git diffutils gcc gcc-c++ pkgconf-pkg-config meson systemd-devel protobuf-c-devel libxkbcommon-devel doxygen python3-attrs python3-pytest python3-dbusmock'
+{% for distro in distributions %}
+  {{distro.name.upper()}}_PACAKGES: '{% for p in distro.packages %}{{p}} {% endfor %}'
+{% endfor %}
   ############################ end of package lists #############################
 
   # these tags should be updated each time the list of packages is updated

.gitlab-ci/config.yml

@@ -11,6 +11,20 @@ distributions:
     versions:
       - '37' # update the pages job when bumping the version
     use_for_custom_build_tests: true
+    packages:
+      - git
+      - diffutils
+      - gcc
+      - gcc-c++
+      - pkgconf-pkg-config
+      - meson
+      - systemd-devel
+      - protobuf-c-devel
+      - libxkbcommon-devel
+      - doxygen
+      - python3-attrs
+      - python3-pytest
+      - python3-dbusmock
 
 pages:
   distro: fedora