ci(earthly): Enable inline caching

images/.utils/gitlab-ci.yaml

@@ -26,7 +26,7 @@ container-build:
       else
         export BUILD_ARGS="${BUILD_ARGS} --tag=$CI_COMMIT_REF_SLUG --latest=false"
       fi
-    - earthly --ci --allow-privileged --push ${ARGS} +container --registry=quay.io/shivering-isles/${IMAGE} ${BUILD_ARGS}
+    - earthly --ci --use-inline-cache --save-inline-cache --allow-privileged --push ${ARGS} +container --registry=quay.io/shivering-isles/${IMAGE} ${BUILD_ARGS}
   rules:
     - if: '$CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH && $CI_PIPELINE_SOURCE == "push"'
       changes: