chore: pass keys to save_key_to_dir as slice (#1002)

chore: pass keys to be saved to file as slice

crates/nargo/src/cli/fs/keys.rs

@@ -7,7 +7,7 @@ use acvm::{acir::circuit::Circuit, hash_constraint_system};
 use std::path::{Path, PathBuf};
 
 pub(crate) fn save_key_to_dir<P: AsRef<Path>>(
-    key: Vec<u8>,
+    key: &[u8],
     key_name: &str,
     key_dir: P,
     is_proving_key: bool,
@@ -80,8 +80,8 @@ mod tests {
         // These values are not meaningful, we just need distinct values.
         let pk: Vec<u8> = vec![0];
         let vk: Vec<u8> = vec![1, 2];
-        save_key_to_dir(pk.clone(), circuit_name, &circuit_build_path, true).unwrap();
-        save_key_to_dir(vk.clone(), circuit_name, &circuit_build_path, false).unwrap();
+        save_key_to_dir(&pk, circuit_name, &circuit_build_path, true).unwrap();
+        save_key_to_dir(&vk, circuit_name, &circuit_build_path, false).unwrap();
 
         save_acir_hash_to_dir(&circuit, circuit_name, &circuit_build_path);
         circuit_build_path.push(circuit_name);

crates/nargo/src/cli/preprocess_cmd.rs

@@ -41,8 +41,8 @@ pub(crate) fn preprocess_with_path<P: AsRef<Path>>(
     // If hash doesn't match then the circuit has been updated and keys are stale.
     save_acir_hash_to_dir(circuit, key_name, &preprocess_dir);
 
-    let pk_path = save_key_to_dir(proving_key, key_name, &preprocess_dir, true)?;
-    let vk_path = save_key_to_dir(verification_key, key_name, preprocess_dir, false)?;
+    let pk_path = save_key_to_dir(&proving_key, key_name, &preprocess_dir, true)?;
+    let vk_path = save_key_to_dir(&verification_key, key_name, preprocess_dir, false)?;
 
     Ok((pk_path, vk_path))
 }