Fix: gitlab_ci_yml_spec.rb hangs on #validation_message

Summary

The Developer Experience (DevEx) team is working on improving pipeline stability EPIC and has identified a recurring failure due to gitlab_ci_yml_spec.rb That's causing significant job timeouts.

Problem Description

The spec file spec/models/blob_viewer/gitlab_ci_yml_spec.rb is expected to take a few minutes to run, but hangs for 60 + minutes before timing out.

Error Details

Here is the error message

Click to view Error logs

# [RSpecRunTime] Starting example group spec/models/blob_viewer/gitlab_ci_yml_spec.rb. Expected to take 1.52 seconds.
BlobViewer::GitlabCiYml
  does not allow STI
  #validation_message
Terminated
WARNING: step_script could not run to completion because the timeout was exceeded. For more control over job and script timeouts see: https://docs.gitlab.com/ci/runners/configure_runners/#set-script-and-after_script-timeouts
ERROR: Job failed: execution took longer than 1h30m0s seconds

Impact

Frequency: 11 occurrences in the last 28 days
Duration: Jobs hang for 60+ minutes before timing out

Related Issue

gitlab-org/quality/analytics/team#145