message: Add test to verify retry of 401s in IMDS client
diff: @@ -989,6 +989,33 @@ pub(crate) mod test {
  connection.assert_requests_match(&[]);
  }
  + /// 401 error during metadata retrieval must be retried
  + #[tokio::test]
  + #[traced_test]
  + async fn retry_metadata_401() {
  + let connection = TestConnection::new(vec![
  + (
  + token_request("http://169.254.169.254", 21600),
  + token_response(0, TOKEN_A),
  + ),
  + (
  + imds_request("http://169.254.169.254/latest/metadata", TOKEN_A),
  + http::Response::builder().status(401).body("").unwrap(),
  + ),
  + (
  + token_request("http://169.254.169.254", 21600),
  + token_response(21600, TOKEN_B),
  + ),
  + (
  + imds_request("http://169.254.169.254/latest/metadata", TOKEN_B),
  + imds_response("ok"),
  + ),
  + ]);
  + let client = make_client(&connection).await;
  + assert_eq!(client.get("/latest/metadata").await.expect("success"), "ok");
  + connection.assert_requests_match(&[]);
  + }
  +
  /// 403 responses from IMDS during token acquisition MUST NOT be retried
  #[tokio::test]
  #[traced_test]
  