minor: fix typo (#1388)

Author: JamieTsai1024

src/error.rs

@@ -47,7 +47,7 @@ pub const UNKNOWN_TRANSACTION_COMMIT_RESULT: &str = "UnknownTransactionCommitRes
 pub type Result<T> = std::result::Result<T, Error>;
 
 /// An error that can occur in the `mongodb` crate. The inner
-/// [`ErrorKind`](enum.ErrorKind.html) is wrapped in an `Arc` to allow the errors to be
+/// [`ErrorKind`](enum.ErrorKind.html) is wrapped in an `Box` to allow the errors to be
 /// cloned.
 #[derive(Clone, Debug, Error)]
 #[cfg_attr(test, error("Kind: {kind}, labels: {labels:?}, backtrace: {bt}"))]