chore: Cleanup warnings and unused functions

harmony_secret/src/store/local_file.rs

@@ -70,7 +70,6 @@ mod tests {
     #[tokio::test]
     async fn test_set_and_get_raw_successfully() {
         let dir = tempdir().unwrap();
-        let store = LocalFileSecretStore::default();
         let ns = "test-ns";
         let key = "test-key";
         let value = b"{\"data\":\"test-value\"}";