Reduce features on lightning-transaction-sync's tokio dev-dep

This should marginally reduce the chance of MSRV or other issues in
the future, and is just good practice.

lightning-transaction-sync/Cargo.toml

@@ -32,7 +32,7 @@ electrum-client = { version = "0.21.0", optional = true }
 
 [dev-dependencies]
 lightning = { version = "0.0.124", path = "../lightning", default-features = false, features = ["std", "_test_utils"] }
-tokio = { version = "1.35.0", features = ["full"] }
+tokio = { version = "1.35.0", features = ["macros"] }
 
 [target.'cfg(not(target_os = "windows"))'.dev-dependencies]
 electrsd = { version = "0.28.0", default-features = false, features = ["legacy"] }