Disable audit event logging for pipeline destruction

AuditEventService isn't equipped to handle logging of the destruction of
entities such as CI pipelines. It's a project-level event that operates
on a pipeline.

Rather than pollute the database with information that doesn't
quite fit in the schema, let's remove it altogether.

app/services/ci/destroy_pipeline_service.rb

@@ -5,15 +5,7 @@ module Ci
     def execute(pipeline)
       raise Gitlab::Access::AccessDeniedError unless can?(current_user, :destroy_pipeline, pipeline)
 
-      AuditEventService.new(current_user, pipeline, audit_details).security_event
-
       pipeline.destroy!
     end
-
-    def audit_details
-      {
-        custom_message: 'Destroyed pipeline'
-      }
-    end
   end
 end

ee/app/services/ee/audit_event_service.rb

@@ -181,12 +181,8 @@ module EE
     end
 
     def add_security_event_admin_details!
-      # TODO: Entities such as projects and groups have a full path that
-      # we can log. However, objects such as CI pipelines do not have
-      # this. We could delegate this to the project path in the future, but
-      # for now, just set it to empty.
       @details.merge!(ip_address: ip_address,
-                      entity_path: @entity.try(:full_path))
+                      entity_path: @entity.full_path)
     end
 
     def custom_project_link_group_attributes(group_link)

spec/requests/api/pipelines_spec.rb

@@ -458,11 +458,11 @@ describe API::Pipelines do
 
       context 'when audit events is enabled' do
         before do
-          stub_licensed_features(extended_audit_events: true)
+          stub_licensed_features(extended_audit_events: true, admin_audit_log: true)
         end
 
-        it 'logs an audit event' do
-          expect { delete api("/projects/#{project.id}/pipelines/#{pipeline.id}", owner) }.to change { SecurityEvent.count }.by(1)
+        it 'does not log an audit event' do
+          expect { delete api("/projects/#{project.id}/pipelines/#{pipeline.id}", owner) }.not_to change { SecurityEvent.count }
         end
       end
 

spec/services/ci/destroy_pipeline_service_spec.rb

@@ -22,13 +22,8 @@ describe ::Ci::DestroyPipelineService do
         stub_licensed_features(extended_audit_events: true, admin_audit_log: true)
       end
 
-      it 'logs an audit event' do
-        expect { subject }.to change { SecurityEvent.count }.by(1)
-
-        event = SecurityEvent.first
-        expect(event.entity_type).to eq('Ci::Pipeline')
-        expect(event.entity_id).to eq(pipeline.id)
-        expect(event.details[:custom_message]).to eq('Destroyed pipeline')
+      it 'does not log an audit event' do
+        expect { subject }.not_to change { SecurityEvent.count }
       end
     end