multi: bump btcd version.

The new SignCompact return values had to be adopted across the
code base.

go.mod

@@ -4,8 +4,8 @@ require (
 	github.com/NebulousLabs/go-upnp v0.0.0-20180202185039-29b680b06c82
 	github.com/Yawning/aez v0.0.0-20211027044916-e49e68abd344
 	github.com/andybalholm/brotli v1.0.4
-	github.com/btcsuite/btcd v0.24.2-beta.rc1.0.20240625142744-cc26860b4026
-	github.com/btcsuite/btcd/btcec/v2 v2.3.3
+	github.com/btcsuite/btcd v0.24.3-0.20240921052913-67b8efd3ba53
+	github.com/btcsuite/btcd/btcec/v2 v2.3.4
 	github.com/btcsuite/btcd/btcutil v1.1.5
 	github.com/btcsuite/btcd/btcutil/psbt v1.1.8
 	github.com/btcsuite/btcd/chaincfg/chainhash v1.1.0