Handle event streaming licence error when no entity

ee/app/models/ee/audit_event.rb

@@ -57,7 +57,7 @@ module EE
     def stream_to_external_destinations
       return if entity.nil?
       return unless ::Feature.enabled?(:ff_external_audit_events_namespace, group_entity)
-      return unless group_entity.licensed_feature_available?(:external_audit_events)
+      return unless group_entity&.licensed_feature_available?(:external_audit_events)
 
       AuditEvents::AuditEventStreamingWorker.perform_async(id)
     end

ee/spec/models/ee/audit_event_spec.rb

@@ -101,6 +101,20 @@ RSpec.describe AuditEvent, type: :model do
 
             event.stream_to_external_destinations
           end
+
+          context 'when entity is not a group or project' do
+            let_it_be(:event) { create(:user_audit_event) }
+
+            before do
+              stub_feature_flags(ff_external_audit_events_namespace: true)
+            end
+
+            it 'enqueues no workers' do
+              expect(AuditEvents::AuditEventStreamingWorker).not_to receive(:perform_async)
+
+              event.stream_to_external_destinations
+            end
+          end
         end
 
         context 'when ff_external_audit_events_namespace is disabled' do