chromium-rust-v0.53 WASM to python-v0.x WebSocket timeout

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**Repos:**
- [libp2p/rust-libp2p](https://github.com/libp2p/rust-libp2p) WASM build (commit `b7914e407da34c99fb76dcc300b3d44b9af97fac`)
- [libp2p/py-libp2p](https://github.com/libp2p/py-libp2p) (commit `22ea173ac0359a386275bdf6b846bc52a0082e91`)

**Transport:** ws, **Secure:** noise, **Muxer:** mplex

## Summary

chromium-rust-v0.53 (WASM build running in Chromium) times out when dialing python-v0.x as listener via ws/noise/mplex. The python listener starts and publishes its multiaddr, but the WASM dialer never successfully connects. The test hits the 180-second timeout.

## Failing tests (1)

- `chromium-rust-v0.53 x python-v0.x (ws, noise, mplex)`

## Error output

```
Test timed out after 180s
```

## Notes

This may be a WASM WebSocket transport incompatibility with the Python implementation. The chromium-rust-v0.53 WASM dialer successfully connects to other implementations (go, rust, js) via ws, so the issue is specific to the python listener. Possible causes include differences in WebSocket subprotocol negotiation or noise handshake timing in the WASM environment.

Start with the failing `chromium-rust-v0.53 x python-v0.x (ws, noise, mplex)` test and the two implementation commits listed in the issue. Compare the WASM dialer and Python listener's WebSocket subprotocol negotiation and Noise handshake behavior, then verify that the test connects successfully without reaching the 180-second timeout.

Written by the indexing model from the issue text.