tapfreighter: make dummy output look like valid P2TR output

In order to be able to pass the dummy outputs to the lnd FundPsbt call
we need to make them look more like actual P2TR outputs.

tapfreighter/chain_porter.go

@@ -830,8 +830,11 @@ func (p *ChainPorter) importLocalAddresses(ctx context.Context,
 func createDummyOutput() *wire.TxOut {
 	// The dummy PkScript is the same size as an encoded P2TR output.
 	newOutput := wire.TxOut{
-		Value:    int64(tapscript.DummyAmtSats),
-		PkScript: make([]byte, 34),
+		Value: int64(tapscript.DummyAmtSats),
+		PkScript: append(
+			[]byte{txscript.OP_1, txscript.OP_DATA_32},
+			make([]byte, 32)...,
+		),
 	}
 	return &newOutput
 }