[merlin, zk-sdk] Turn default-features for merlin crate to false (#4469)

turn default-features for `merlin` crate to false

Author: samkim-crypto

Cargo.toml

@@ -2,7 +2,7 @@
 inherits = "release"
 debug = true
 split-debuginfo = "packed"
-lto = false # Preserve the 'thin local LTO' for this build.
+lto = false                # Preserve the 'thin local LTO' for this build.
 
 [profile.release]
 split-debuginfo = "unpacked"
@@ -374,7 +374,7 @@ lru = "0.7.7"
 lz4 = "1.28.1"
 memmap2 = "0.5.10"
 memoffset = "0.9"
-merlin = "3"
+merlin = { version = "3", default-features = false }
 min-max-heap = "1.3.0"
 mockall = "0.11.4"
 modular-bitfield = "0.11.2"

zk-sdk/src/lib.rs

@@ -24,6 +24,7 @@ pub mod errors;
 pub mod pod;
 mod range_proof;
 mod sigma_proofs;
+#[cfg(not(target_os = "solana"))]
 mod transcript;
 pub mod zk_elgamal_proof_program;
 

zk-sdk/src/transcript.rs

@@ -1,8 +1,7 @@
-use merlin::Transcript;
-#[cfg(not(target_os = "solana"))]
 use {
     crate::errors::TranscriptError,
     curve25519_dalek::{ristretto::CompressedRistretto, scalar::Scalar, traits::IsIdentity},
+    merlin::Transcript,
 };
 
 pub trait TranscriptProtocol {