ci: Install gjs from git

While we don't actually require the newer version, there was some
fallout from its change to optimize GObject property accesses by
calling the getter function.

Including that change in the CI image (and therefore derived toolbox
images) should give it more test exposure, so we can hopefully
find remaining issues (if any) before the release.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4268>

.gitlab-ci.yml

@@ -106,7 +106,7 @@ variables:
     - .skip-git-clone
   variables:
     FDO_DISTRIBUTION_VERSION: 41
-    BASE_TAG: '2025-02-04.1'
+    BASE_TAG: '2025-02-12.1'
     MUTTER_USER: 'meta-user'
     FDO_DISTRIBUTION_PACKAGES:
       accountsservice-devel

.gitlab-ci/install-common-dependencies.sh

@@ -141,3 +141,11 @@ then
       https://gitlab.gnome.org/GNOME/gdm.git \
       main
 fi
+
+if ! pkgconf --atleast-version 1.83.4 gjs-1.0
+then
+    ./$SCRIPTS_DIR/install-meson-project.sh \
+      "${OPTIONS[@]}" \
+      https://gitlab.gnome.org/GNOME/gjs.git \
+      master
+fi