Fix pipeline schedule when owner is nil

Fixing the bug

app/services/ci/pipeline_schedule_service.rb

@@ -7,7 +7,7 @@ module Ci
       # Otherwise, multiple pipelines could be created in a short interval.
       schedule.schedule_next_run!
-      RunPipelineScheduleWorker.perform_async(schedule.id, schedule.owner.id)
+      RunPipelineScheduleWorker.perform_async(schedule.id, schedule.owner&.id)
     end
   end
 end

changelogs/unreleased/fix-pipeline-schedule-owner-is-nil.yml

+---
+title: Fix pipeline schedules when owner is nil
+merge_request:
+author:
+type: fixed

spec/services/ci/pipeline_schedule_service_spec.rb

@@ -24,5 +24,13 @@ describe Ci::PipelineScheduleService do
       subject
     end
+
+    context 'when owner is nil' do
+      let(:schedule) { create(:ci_pipeline_schedule, project: project, owner: nil) }
+
+      it 'does not raise an error' do
+        expect { subject }.not_to raise_error
+      end
+    end
   end
 end