apt: get updated list of packages

.gitlab-ci.yml

@@ -48,6 +48,7 @@ workflow:
 .ubuntu-template-job-default: &ubuntu-job
   image: gitlab-registry.cern.ch/geomodeldev/ubuntu-geant4-image:main-base
   before_script: 
+    - sudo apt-get update && sudo apt-get dist-upgrade
     - sudo apt-get update && apt-get install -y libgtest-dev
   rules:
     - if: $CI_PIPELINE_SOURCE == "merge_request_event"