ci: simplify integration test runner job
ci: easily identify to which project runners belong
ci: use CI_PIPELINE_IID instead of CI_PIPELINE_ID to identify the pipeline
The project-internal pipeline IID is defined by the time the jobs are
created, unlike the instance-global pipeline ID, which allows the next
commit to simplify the whole pipeline.
Combined with `$CI_PROJECT_ID`, this allows the tag to remain globally
unique.
ci: simplify integration test runner job
As of last commit, it is now possible to define the job directly in the
same pipeline, allowing us to get rid of the entire child pipeline.
Edited by Eric Engestrom