[CI] why some MRs are running detached pipelines when that feature is not enabled for this project

Summary

We've noticed in #2976 (closed) ( !2238 (merged) ) that adding a job to existing pipeline triggered detached pipeline as described in Pipelines for merged results despite the fact that the feature is not enabled for the project directly.

Steps to reproduce

• Create MR
• modify pipeline adding "extra" job with no rules

Configuration used

Current behavior

• observe detached pipeline being run that will include that job alone

Expected behavior

• no detached pipelines since feature is not enabled

Versions

• Chart: (tagged version | branch | hash git rev-parse HEAD)
• Platform:
  • Cloud: (GKE | AKS | EKS | ?)
  • Self-hosted: (OpenShift | Minikube | Rancher RKE | ?)
• Kubernetes: (kubectl version)
  • Client:
  • Server:
• Helm: (helm version)
  • Client:
  • Server:

Relevant logs