fix: support for gitlab-ci-local

.gitlab-ci.yml

 image: eicweb.phy.anl.gov:4567/containers/image_recipes/ubuntu_dind:latest
 
 variables:
+  ## External images
+  DOCKER_IMAGE: docker.io/docker:24.0.5
+  SINGULARITY_IMAGE: quay.io/singularity/singularity:v3.11.4
+
   ## Application versions used for the main release 
   ## note: nightly builds will always use the master/main branch
   JUGGLER_VERSION: "v10.0.1"