CI: Update configuration

Update:
 * images
 * template path
 * flatpak stage configuration

.gitlab-ci.yml

@@ -1,42 +1,23 @@
-include: 'https://gitlab.gnome.org/GNOME/citemplates/raw/master/flatpak/flatpak_ci_initiative.yml'
+include:
+  - project: "GNOME/citemplates"
+    file: "flatpak/flatpak-ci-initiative-sdk-extensions.yml"
 
-stages:
-  - check
-  - test
-  - deploy
-
-variables:
+flatpak:
+  variables:
     BUNDLE: "org.gnome.Loupe.Devel.flatpak"
     MANIFEST_PATH: "build-aux/flatpak/org.gnome.Loupe.Devel.json"
     FLATPAK_MODULE: "loupe"
-    FLATPAK_IMAGE: "registry.gitlab.gnome.org/gnome/gnome-runtime-images/rust_bundle:master"
-
-.flatpak_cache_template: &flatpak_cache
-    cache:
-        key: "flatpak"
-        paths:
-          - .flatpak-builder/cache/
-          - _build/target/
-
-check:
-    image: "registry.gitlab.com/alatiera/rustfmt-oci-image/rustfmt:stable"
-    stage: "check"
-    script:
-        # Create blank versions of our configured files
-        # so rustfmt does not yell about non-existent files or completely empty files
-        - echo -e "" >> src/config.rs
-        - rustc -Vv && cargo -Vv
-        - cargo --version
-        - cargo fmt --all -- --check
-
-flatpak:
-  extends: '.flatpak'
-  image: "$FLATPAK_IMAGE"
-  variables:
-    RUNTIME_REPO: 'https://nightly.gnome.org/gnome-nightly.flatpakrepo'
     APP_ID: "org.gnome.Loupe.Devel"
+    RUNTIME_REPO: "https://nightly.gnome.org/gnome-nightly.flatpakrepo"
+  extends: ".flatpak"
 
-# nightly:
-#   extends: '.publish_nightly'
-#   dependencies: ['flatpak']
-#   needs: ['flatpak']
+rustfmt:
+  image: "rust:slim"
+  script:
+    - rustup component add rustfmt
+    # Create blank versions of our configured files
+    # so rustfmt does not yell about non-existent files or completely empty files
+    - echo -e "" >> src/config.rs
+    - rustc -Vv && cargo -Vv
+    - cargo fmt --version
+    - cargo fmt --all -- --check