Early branch: Adjust the verify_pre_deployment job to wait on the pre deploy pipeline

Context

The verify_pre_deployment job is not aligned with the pre deployment triggered after tagging a release candidate. When testing the release candidate automation on #21327 (closed), a notification was sent to Slack stating the pre environment was running on the 18.2 RC42:

Screenshot_2025-07-15_at_1.27.05_p.m.

Reviewing the version running on pre, we can see it is in fact running said version:

Screenshot_2025-07-15_at_1.04.17_p.m.

However, at that point in time, the pre deployer pipeline was still running:

Pre pipeline: https://ops.gitlab.net/gitlab-com/gl-infra/deployer/-/pipelines/4731896

Screenshot_2025-07-15_at_1.02.59_p.m.

The slack notification is inaccurate as the deployment could fail further down the line, on post-deploy migrations, or QA.

The issue is to update the logic invoked by the verify_pre_deployment to:

  1. Find the pre deployment pipeline
  2. Wait for it to finish
  3. Report the status of the pipeline on the slack notification.

This issue should also consider increasing the delay time to account for post-deploy migrations and quality specs executed on pre

Acceptance criteria

  • Implement a method to verify Pre deployment by waiting for the deployment pipeline kicked off after tagging
  • Remove the old deployment validation class, which checks the version deployed on a GitLab instance
Edited by Siddharth Kannan