Next try on CI fix, added apt update, through this might be slow.

.gitlab-ci.yml

@@ -13,7 +13,7 @@ stages:
     - ls
     - python -V
     - pip -V
-    - apt-get install build-essential
+    - apt-get update && apt-get install build-essential
     #- git clone https://$clone_token@gitlab.hzdr.de/hmc/hmc/cct-1-mapping/category-definitions.git
     #- pip install ./category-definitions
     - pip install poetry