wasm-pack build fails for WebRTC + gossipsub in libp2p v0.56.0 due to ahash → getrandom v0.3.4

## Summary When building a WASM P2P node with `gossipsub` and `webrtc-websys` in libp2p v0.56.0, the build fails due to an unresolved `getrandom` backend requirement, even though all correct features are enabled. This blocks browser-to-browser gossipsub in WASM until either: - The `ahash` dependency is fully removed from `gossipsub`, or - Proper WebRTC transport APIs are exposed in `SwarmBuilder`. ## Steps to Reproduce 1. Create a minimal WASM crate with: ```toml [dependencies.libp2p] version = "0.56.0" default-features = false features = [ "webrtc-websys", "noise", "wasm-bindgen", "gossipsub" ] 2. Implement a basic NetworkBehaviour with gossipsub::Behaviour 3. Try to build with:wasm-pack build --target web 4.Expected Behavior Compiles successfully (as implied by docs and examples) WebRTC transport works via .with_webrtc() or equivalent Actual Behavior Error 1: Missing .with_webrtc() method error[E0599]: no method named `with_webrtc` found for struct `SwarmBuilder<...>` Error 2: getrandom v0.3.4 fails in WASM This happens because: libp2p-gossipsub v0.49.2 → hashlink → hashbrown → ahash → getrandom v0.3.4 ahash does not enable the wasm_js feature on its getrandom dependency Even if I add getrandom = { version = "0.3.4", features = ["wasm_js"] }, Cargo doesn’t propagate the feature to transitive deps Workarounds Tried ✅ Removing gossipsub → compiles (but loses pubsub) ✅ Using websocket-websys instead → works, but requires relay ❌ Adding "serde" or "other" features → doesn’t fix missing .with_webrtc() ❌ Patching getrandom → fails due to ahash hard dependency Environment libp2p version: 0.56.0 Rust version: rustc 1.83.0 (or latest stable) Target: wasm32-unknown-unknown OS: Windows 11 (but reproducible on Linux/macOS) Additional Context PR #5098 replaced ahash with fxhash, which should fix the getrandom issue However, v0.56.0 still uses ahash, and there’s no published version with the fix Also, the WebRTC transport API (SwarmBuilder::with_webrtc()) appears to be missing or unstable Request Release v0.57.0 with the ahash → fxhash migration (from #5098) Document the correct way to use WebRTC in WASM — current examples reference .with_webrtc(), but it doesn’t exist in v0.56.0 Clarify whether gossipsub is truly WASM-compatible today Thank you for your work on libp2p