Remove incorrect usage of GitLab

doc/api/merge_trains.md

doc/ci/caching/index.md

doc/ci/examples/authenticating-with-hashicorp-vault/index.md

...i/examples/devops_and_game_dev_with_gitlab_ci_cd/index.md

doc/ci/introduction/index.md

doc/ci/pipelines/job_artifacts.md

doc/ci/pipelines/settings.md

doc/ci/triggers/README.md

doc/ci/variables/README.md

doc/ci/variables/predefined_variables.md

doc/ci/variables/where_variables_can_be_used.md

doc/ci/yaml/README.md

...development/documentation/site_architecture/global_nav.md

doc/development/documentation/site_architecture/index.md

doc/development/documentation/structure.md

doc/development/documentation/testing.md

doc/development/documentation/workflow.md

doc/user/project/new_ci_build_permissions_model.md