Remove .eligible scope

In this case we actually expect there to be no payment fee adjustments at all on the payment, regardless of their eligibility.

spec/models/spree/payment_spec.rb

@@ -414,7 +414,7 @@
           it "should not applied any transaction fees" do
             payment.credit!
             expect(payment.adjustment.finalized?).to eq(false)
-            expect(order.all_adjustments.payment_fee.eligible.length).to eq(0)
+            expect(order.all_adjustments.payment_fee.length).to eq(0)
           end
         end