Using local debian repo: Speed up the image building.

Summary

Using the local package repositories.

Focus

Is such a hard coded repository acceptable?

Test Environment

Look at pipeline job: https://gitlab.indiscale.com/caosdb/src/caosdb-pylib/-/jobs/135250

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related issues #142 (closed)
• Up-to-date CHANGELOG.md (or not necessary)
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md (or not necessary)
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there specifications? Are they satisfied?

For further good practices have a look at our review guidelines.

.gitlab-ci.yml

@@ -86,8 +86,8 @@ build-testenv:
   tags: [ cached-dind ]
   image: docker:19.03
   stage: setup
-  # only:
-  #     - schedules
+  only:
+      - schedules
   script: 
     - cd unittests/docker
     - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY