Function http_quic_handler_fn 

async fn http_quic_handler_fn(
    connection_attempt: Incoming,
    client_address: SocketAddr,
    server_address: SocketAddr,
    configurations: Arc<ServerConfigurations>,
    quic_tls_configs: Arc<HashMap<(Option<IpAddr>, u16), Arc<ServerConfig>>>,
    connection_reference: Arc<()>,
    shutdown_rx: CancellationToken,
    graceful_shutdown_token: Arc<CancellationToken>,
)

HTTP/3 handler function