Cancel job instead of pipeline.
What does this MR do and why?
When there are no pending post-migrations or the production checks have failed, one of the initial jobs of the post-deploy pipeline will be canceled, which should cancel the pipeline preventing the post-deploy pipeline to be executed.
It also fixes the Slack message to use the proper icon.
Related to gitlab-com/gl-infra/delivery#2441 (closed)
Author Check-list
- [-] Has documentation been updated?
Edited by Mayra Cabrera