chore: remove env_logger from hyper example

Currently, the `hyper_echo` example uses the `tracing-log` env logger
support for some weird reason. I believe this is due to Hyper previously
using `log` rather than `tracing`. However, `hyper` now emits native
`tracing` diagnostics, so all the `env_logger` nonsense can just be
removed from the example.

This branch does that.

examples/Cargo.toml

@@ -30,9 +30,6 @@ serde_json = "1.0.82"
 futures = "0.3.21"
 tokio = { version = "1.20.0", features = ["full"] }
 
-# env-logger example
-env_logger = "0.8.4"
-
 # tower examples
 tower = { version = "0.4.13", features = ["full"] }
 http = "0.2.8"