chore: benches_rt/tokio: set event_interval to 1

[kanarus]

I found that in very simple senario, like getting a path param and echoing it as text, the higher setting event_interval of tokio runtime, the lower the performance be.
So this PR tries setting it to the minimum value, 1, in benches_rt/tokio/src/bin/param ( default: 61 ).

ref: https://docs.rs/tokio/1.39.3/tokio/runtime/struct.Builder.html#method.event_interval

benchmark examples

wrk -H 'Connection: keep-alive' --connections 32 --threads 16 --duration 3s --timeout 1s 'http://localhost:3000/user/1234567890987654321'

• default ( #[tokio::main] async fn main() )

  1. Requests/sec: 725217.89
  2. Requests/sec: 726961.24
  3. Requests/sec: 724529.73

• set event_interval to 1 ( .event_interval(1) )

  1. Requests/sec: 874318.85
  2. Requests/sec: 865562.96
  3. Requests/sec: 848599.67