"Invalid Server Name" when requesting an IPv6 literal through a proxy

use tokio::io::{AsyncReadExt, AsyncWriteExt};

// A CONNECT proxy that accepts the tunnel and holds the socket open.
async fn proxy() -> std::net::SocketAddr {
    let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
    let addr = listener.local_addr().unwrap();

    tokio::spawn(async move {
        while let Ok((mut sock, _)) = listener.accept().await {
            let mut buf = [0u8; 1024];
            let _ = sock.read(&mut buf).await;
            let _ = sock
                .write_all(b"HTTP/1.1 200 Connection Established\r\n\r\n")
                .await;

            tokio::spawn(async move {
                let mut sink = [0u8; 1024];
                while sock.read(&mut sink).await.unwrap_or(0) != 0 {}
            });
        }
    });

    addr
}

#[tokio::main]
async fn main() {
    let proxy = proxy().await;
    let client = reqwest::Client::builder()
        .proxy(reqwest::Proxy::https(format!("http://{proxy}")).unwrap())
        .timeout(std::time::Duration::from_secs(2))
        .build()
        .unwrap();

    for url in ["https://[2001:db8::1]/", "https://192.0.2.1/"] {
        println!("{url}\n  {:?}\n", client.get(url).send().await.unwrap_err());
    }
}

[dependencies]
reqwest = { version = "0.13.4", features = ["rustls"] }
tokio = { version = "1", features = ["full"] }