Fix `add_job_service` to also update project of metadata

In some cases `metadata` object might already be provisioned.
This ensures that metadata is properly configured.

app/services/ci/pipelines/add_job_service.rb

@@ -39,6 +39,12 @@ module Ci
         job.pipeline = pipeline
         job.project = pipeline.project
         job.ref = pipeline.ref
+
+        # update metadata since it might have been lazily initialised before this call
+        # metadata is present on `Ci::Processable`
+        if job.respond_to?(:metadata) && job.metadata
+          job.metadata.project = pipeline.project
+        end
       end
     end
   end

spec/services/ci/pipelines/add_job_service_spec.rb

@@ -31,7 +31,7 @@ RSpec.describe Ci::Pipelines::AddJobService do
         execute
       end.to change { job.slice(:pipeline, :project, :ref) }.to(
         pipeline: pipeline, project: pipeline.project, ref: pipeline.ref
-      )
+      ).and change { job.metadata.project }.to(pipeline.project)
     end
 
     it 'returns a service response with the job as payload' do