Merge branch 'make-use-of-plan-variable-in-spec-setup' into 'master'

Make use of existing but unused variable in specs

See merge request gitlab-org/gitlab!38875

ee/spec/features/billings/billing_plans_spec.rb

@@ -114,7 +114,7 @@ RSpec.describe 'Billing plan pages', :feature do
       let(:plan) { free_plan }
 
       let!(:subscription) do
-        create(:gitlab_subscription, namespace: namespace, hosted_plan: nil, seats: 15)
+        create(:gitlab_subscription, namespace: namespace, hosted_plan: plan, seats: 15)
       end
 
       before do