Function run_concurrently 

pub async fn run_concurrently<HF, GF, HE, GE>(
    http_future: HF,
    grpc_future: GF,
) -> Result<()>
where
    HF: Future<Output = Result<(), HE>> + Send,
    GF: Future<Output = Result<(), GE>> + Send,
    HE: Error + Send + Sync + 'static,
    GE: Error + Send + Sync + 'static,

Run two independent servers/tasks concurrently.

This is useful for running a RustAPI HTTP server together with a Tonic gRPC server.

The function returns when one of the futures returns an error, or when both complete successfully.