32912eaa05Don't default to use `async`/`await` on `wasm32` (Elias Rohrer) Pull request description: ### Description We don't automatically want to make the interface `async` based on the used architecture, but now require the user to explicitly set the `async-interface` feature. #### All Submissions: * [x] I've signed all my commits * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md) * [x] I ran `cargo fmt` and `cargo clippy` before committing ACKs for top commit: notmandatory: ACK32912eaa05Tree-SHA512: 41a8f3ab29508a359a8c0d96994e4fa97e52c15e8b8003c1988bcfe036cafa81d6210d446ed825672ce52aff684ebb328dc61b8ae3d25cda6f51a3cae838de58