test: add ics20 memo field to test vector strategy

crates/core/transaction/tests/generate_transaction_signing_test_vectors.rs

@@ -558,6 +558,7 @@ fn ics20_withdrawal_strategy() -> impl Strategy<Value = Ics20Withdrawal> {
                 source_channel: ChannelId::default(),
                 use_compat_address: false,
                 use_transparent_address: true,
+                ics20_memo: "".to_string(),
             },
         )
 }