feat(wasm-utxo): add dependencies for better testing

Added serde, serde_json, and hex crates to dev-dependencies to enhance
test capabilities in the wasm-utxo package.

Co-authored-by: llm-git <[email protected]>

Issue: BTC-2652

Author: OttoAllmendinger

packages/wasm-utxo/Cargo.lock

@@ -13,6 +13,9 @@ miniscript = { git = "https://github.com/BitGo/rust-miniscript", branch = "opdro
 
 [dev-dependencies]
 base64 = "0.22.1"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+hex = "0.4"
 
 [profile.release]
 # this is required to make webpack happy