Audit pipeline delete action

What does this MR do and why?

This MR logs the audit event when the pipeline is deleted in a project.

Related issue: #339041 (closed)

Screenshots or screen recordings

How to set up and validate locally

1. Navigate to any project and create a pipeline
2. Navigate to the project pipelines page (Build -> Pipelines) or /pipelines path
3. Open the pipeline and select the Delete option
4. Verify the audit events in the Secure -> Audit events page.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.