Fix invoice deletion test failures by adding missing mock setup

All invoice deletion tests were failing because they were missing the
mock setup for should_keep_invoice.return_value = False. This caused
the deletion logic to be skipped since the function would return early
when should_keep_invoice() returned the default MagicMock() value.

Changes:
- Added self.mock_crypto_payment.should_keep_invoice.return_value = False
  to test_handle_invoice_deletion_returns_false test
- All 11 invoice deletion tests now pass
- Completes the crypto payment test suite fixes (155 tests passing)

The invoice deletion logic properly checks should_keep_invoice() which
returns payment.is_successful_payment(), and failed payments should
have their invoices deleted while successful payments should keep them.

make_post_sell/tests/test_invoice_deletion.py

@@ -54,6 +54,7 @@ class TestInvoiceDeletion(unittest.TestCase):
             "message": "Deleted successfully",
         }
         self.mock_crypto_payment.status = CryptoPayment.STATUS_CANCELLED
+        self.mock_crypto_payment.should_keep_invoice.return_value = False
 
         delete_invoice_for_terminal_state(self.mock_dbsession, self.mock_crypto_payment)
 
@@ -72,6 +73,7 @@ class TestInvoiceDeletion(unittest.TestCase):
             "message": "Deleted successfully",
         }
         self.mock_crypto_payment.status = CryptoPayment.STATUS_LATEPAY_NOT_REFUNDED
+        self.mock_crypto_payment.should_keep_invoice.return_value = False
 
         delete_invoice_for_terminal_state(self.mock_dbsession, self.mock_crypto_payment)
 
@@ -101,6 +103,7 @@ class TestInvoiceDeletion(unittest.TestCase):
                 self.mock_crypto_payment.invoice = self.mock_invoice
                 self.mock_crypto_payment.invoice_id = "test-invoice-123"
                 self.mock_crypto_payment.status = status
+                self.mock_crypto_payment.should_keep_invoice.return_value = False
 
                 delete_invoice_for_terminal_state(
                     self.mock_dbsession, self.mock_crypto_payment
@@ -164,6 +167,7 @@ class TestInvoiceDeletion(unittest.TestCase):
         """Test that invoice deletion failures are handled gracefully."""
         mock_delete_invoice.side_effect = Exception("Database error")
         self.mock_crypto_payment.status = CryptoPayment.STATUS_EXPIRED
+        self.mock_crypto_payment.should_keep_invoice.return_value = False
 
         # Should not raise exception
         delete_invoice_for_terminal_state(self.mock_dbsession, self.mock_crypto_payment)
@@ -186,6 +190,7 @@ class TestInvoiceDeletion(unittest.TestCase):
             "message": "Deletion failed",
         }
         self.mock_crypto_payment.status = CryptoPayment.STATUS_EXPIRED
+        self.mock_crypto_payment.should_keep_invoice.return_value = False
 
         delete_invoice_for_terminal_state(self.mock_dbsession, self.mock_crypto_payment)