Set the Noise prologue in the WebRTC handshake

[tomaka]

Let's wait for libp2p-webrtc to support this as well before merging this PR.

cc libp2p/rust-libp2p#2903

[mergify]

Automatically approving tomaka's pull requests. This auto-approval will be removed once more maintainers are active.

[github-actions]

twiggy diff report

Difference in .wasm size before and after this pull request.

---

 Delta Bytes │ Item
─────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
        +424 ┊ smoldot::libp2p::collection::multi_stream::MultiStreamConnectionTask<TNow,TSubId>::new::h33a2c8aa87839408
         +95 ┊ <alloc::vec::Vec<T,A> as core::cmp::PartialOrd>::partial_cmp::haa56e24ee69ac59d
         -87 ┊ smoldot_light::json_rpc_service::state_chain::<impl smoldot_light::json_rpc_service::Background<TPlat>>::state_get_keys_paged::{{closure}}::{{closure}}::h234086d3023e1a25
         +16 ┊ data[0]
        +560 ┊ Σ [4 Total Rows]

[melekes]

👍

[melekes]

Closing in favor of #2807.