How can caching and artifacts speed up Merging vs Rebase on GitLab CI?

        # Example GitLab CI configuration for caching artifacts
        cache:
          paths:
            - vendor/
            - node_modules/

        stages:
          - build
          - test

        build_job:
          stage: build
          script:
            - composer install
            - npm install
          artifacts:
            paths:
              - vendor/
              - node_modules/

        test_job:
          stage: test
          dependencies:
            - build_job
          script:
            - phpunit tests/