Maintanance: Use simplified gossip setup

[Septias]

The iroh-gossip crates shows a simplified version of gossip bootstrapping:

use iroh::{protocol::Router, Endpoint};
use iroh_gossip::{net::Gossip, ALPN};

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    // create an iroh endpoint that includes the standard discovery mechanisms
    // we've built at number0
    let endpoint = Endpoint::builder().discovery_n0().bind().await?;

    // build gossip protocol
    let gossip = Gossip::builder().spawn(endpoint.clone()).await?;

    // setup router
    let router = Router::builder(endpoint.clone())
        .accept(ALPN, gossip.clone())
        .spawn();
    // do fun stuff with the gossip protocol
    router.shutdown().await?;
    Ok(())
}

I have not looked into this yet, but it might be worth investigating if we can follow the same router based approach. This way we could possibly remove the explicit channel usage.

[link2xt]

How is this different from what we are currently doing in init_peer_channels?