Refactor GraduationJob test to be more resilient

The previous implementation of the job depended on starting with
Fedora in a clean state by using the `:clean` tag.  Erasing Fedora
is an expensive operation that we'd like to avoid when possible.

This change set captures the specific ID of the ETD created for the
test so that we don't have to rely on a clean Fedora environment and
assuming the `last` created ETD is the right one to test..

spec/jobs/graduation_job_with_embargo_spec.rb

@@ -6,7 +6,7 @@
 # * update the embargo release date to the user's graduation date plus
 #   their requested embargo length
 # * send notifications
-describe GraduationJob, :clean, integration: true do
+describe GraduationJob, integration: true do
   context "a student with a requested embargo", :perform_jobs do
     let(:w) { WorkflowSetup.new("#{fixture_path}/config/emory/superusers.yml", "#{fixture_path}/config/emory/candler_admin_sets.yml", "/dev/null") }
     let(:user)       { FactoryBot.create(:user) }
@@ -38,9 +38,10 @@
       allow(Hyrax::Workflow::DegreeAwardedNotification).to receive(:send_notification)
       ActiveJob::Base.queue_adapter.filter = [AttachFilesToWorkJob]
       Hyrax::CurationConcern.actor.create(env)
+      @etd_with_embargo_requested = env.curation_concern.id
     end
     it "performs the graduation process" do
-      etd = Etd.last
+      etd = Etd.find(@etd_with_embargo_requested)
       expect(etd.degree_awarded).to eq nil
       expect(etd.embargo.embargo_release_date).to eq six_years_from_today
       expect(etd.embargo_length).to eq "6 months"