Redo using reference instead of anchor

ci-templates/core.yml

@@ -15,7 +15,8 @@ services:
   - name: tecnalia-docker-dev.artifact.tecnalia.com/docker:dind
     alias: docker
 
-.lfs_setup_template: &lfs_setup_definition # Hidden key that defines an anchor
+.lfs_setup_template:
+  variables:
     AFTER_SETUP_UPSTREAM_WORKSPACE: "bash <(curl -s https://packagecloud.io/install/repositories/github/git-lfs/script.deb.sh);\
                   apt install -qq -y git-lfs; \
                   git config --global credential.helper store; \