Use Alpine rather than Fedora for CI

.gitlab-ci.yml

@@ -2,18 +2,17 @@
 #
 # SPDX-License-Identifier: CC0-1.0
 flatpak:
-  image: fedora:latest
+  image: alpine:latest
   stage: build
   variables:
     MANIFEST_PATH: "build-aux/uk.me.bcowan.Rugby.yml"
     RUNTIME_REPO: "https://flathub.org/repo/flathub.flatpakrepo"
     FLATPAK_MODULE: "rugby"
     BUNDLE: "rugby.flatpak"
-    MESON_ARGS: ""
-    DBUS_ID: "uk.me.bcowan.Rugby"
+    APP_ID: "uk.me.bcowan.Rugby"
 
   script:
-  - dnf install -y flatpak-builder
+  - apk update && apk add flatpak-builder
   - flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
   - flatpak install -y flathub org.gnome.Platform 40
   - flatpak install -y flathub org.gnome.Sdk 40
@@ -21,7 +20,7 @@ flatpak:
   - flatpak build app meson --prefix=/app ${MESON_ARGS} _build
   - flatpak build app ninja -C _build install
   - flatpak-builder --finish-only --repo=repo app ${MANIFEST_PATH}
-  - flatpak build-bundle repo ${BUNDLE} --runtime-repo=${RUNTIME_REPO} ${DBUS_ID}
+  - flatpak build-bundle repo ${BUNDLE} --runtime-repo=${RUNTIME_REPO} ${APP_ID}
   artifacts:
     paths:
     - ${BUNDLE}