fix: drop geth's stderr handle

[mattsse]

same as #1985 but for stderr because geth logs everything to stderr

closes #2091

@gnapoli23 could you perhaps try this?

[gnapoli23]

@mattsse

Not working. I checked with a simple test:

#[tokio::test]
async fn test_geth_connection() {
    let geth = Geth::new().dev().spawn();
    let provider = ProviderBuilder::new().on_http(geth.endpoint_url());

    let _ = provider.get_block_number().await.unwrap();
}

It's unable to get the connection through the provider:

thread 'http::test_geth_connection' panicked at crates/provider/tests/it/http.rs:9:47:
called `Result::unwrap()` on an `Err` value: Transport(Custom(reqwest::Error { kind: Request, url: "http://localhost:45635/", source: hyper_util::client::legacy::Error(Connect, ConnectError("tcp connect error", Os { code: 111, kind: ConnectionRefused, message: "Connection refused" })) }))