lnwallet: turn off RBF detection in test

lnwallet/test/test_interface.go

@@ -1758,7 +1758,10 @@ func testPublishTransaction(r *rpctest.Harness,
 		tx3, tx3Spend *wire.MsgTx
 	)
 	t.Run("rbf_tests", func(t *testing.T) {
-		for _, rbf := range []bool{false, true} {
+		// Starting with bitcoind v28.0 and later, mempool full RBF is
+		// turned on, so there's no way to _not_ signal RBF anymore.
+		const rbf = true
+
 		// Now we'll try to double spend an output with a
 		// different transaction. Create a new tx and publish
 		// it. This is the output we'll try to double spend.
@@ -1807,15 +1810,9 @@ func testPublishTransaction(r *rpctest.Harness,
 
 		err = alice.PublishTransaction(tx5, labels.External)
 
-			// If RBF is not enabled, we expect this to be rejected
-			// because it is a double spend.
-			expectedErr := lnwallet.ErrDoubleSpend
-
-			// If RBF is enabled, we expect it to be rejected
-			// because it doesn't pay enough fees.
-			if rbf {
-				expectedErr = chain.ErrInsufficientFee
-			}
+		// We expect it to be rejected/ because it doesn't pay enough
+		// fees.
+		expectedErr := chain.ErrInsufficientFee
 
 		// Assert the expected error.
 		require.ErrorIsf(t, err, expectedErr, "has rbf=%v", rbf)
@@ -1836,19 +1833,13 @@ func testPublishTransaction(r *rpctest.Harness,
 		require.NoError(t, err)
 
 		// Expect rejection in non-RBF case.
-			expErr := lnwallet.ErrDoubleSpend
-			if rbf {
-				// Expect success in rbf case.
-				expErr = nil
 		tx3Spend = tx6
-			}
 		err = alice.PublishTransaction(tx6, labels.External)
-			require.ErrorIs(t, err, expErr)
+		require.NoError(t, err)
 
 		// Mine the tx spending tx3.
 		err = mineAndAssert(r, tx3Spend)
 		require.NoError(t, err)
-		}
 	})
 
 	t.Run("tx_double_spend", func(t *testing.T) {
@@ -3071,9 +3062,9 @@ func testSingleFunderExternalFundingTx(miner *rpctest.Harness,
 	)
 }
 
-// TestInterfaces tests all registered interfaces with a unified set of tests
-// which exercise each of the required methods found within the WalletController
-// interface.
+// TestLightningWallet tests all registered interfaces with a unified set of
+// tests which exercise each of the required methods found within the
+// WalletController interface.
 //
 // NOTE: In the future, when additional implementations of the WalletController
 // interface have been implemented, in order to ensure the new concrete