Tweak specs and remove label return

ee/app/workers/incident_management/apply_incident_sla_exceeded_label_worker.rb

@@ -18,8 +18,6 @@ module IncidentManagement
 
       incident.labels << label
       add_resource_event
-
-      label
     end
 
     private

ee/spec/workers/incident_management/apply_incident_sla_exceeded_label_worker_spec.rb

@@ -21,20 +21,18 @@ RSpec.describe IncidentManagement::ApplyIncidentSlaExceededLabelWorker do
       incident.labels << label
     end
 
-    it 'does not add a label' do
+    it 'does not add a label', :aggregate_failures do
       expect { subject }.not_to change { incident.labels.reload.count }
+      expect(incident.labels.reload).to include(label)
     end
   end
 
-  it 'adds a label to the incident' do
+  it 'adds a label to the incident', :aggregate_failures do
     expect { perform }.to change { incident.labels.reload.count }.by(1)
-
-    expected_label = project.labels.find_by!(IncidentManagement::CreateIncidentSlaExceededLabelService::LABEL_PROPERTIES)
-
-    expect(perform).to eq(expected_label)
+    expect(incident.labels.reload).to include(label)
   end
 
-  it 'adds a note that the label was added' do
+  it 'adds a note that the label was added', :aggregate_failures do
     expect { subject }.to change { incident.resource_label_events.reload.count }
 
     event = incident.resource_label_events.first