blockbook: update Rust crate tokio-tungstenite to 0.20.0

Previous `tokio-tungstenite` versions depend transitively
on `webpki` which is vulnerable to CPU denial of service
attacks [1].

[1] https://rustsec.org/advisories/RUSTSEC-2023-0052

CHANGELOG.md

@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Allowed a `blockbook::TransactionSpecific` to be converted into a `bitcoin::Transaction`.
 - Renamed both rest and websocket clients from `Blockbook` to `Client`.
 - Renamed `blockbook::Client::send_transaction` to `blockbook::Client::broadcast_transaction`.
+- Bumped `tokio-tungstenite` to version 0.20.0 that is not vulnerable to
+  https://rustsec.org/advisories/RUSTSEC-2023-0052 via the `webpki` crate.
 
 ## 0.1.0
 

Cargo.toml

@@ -22,7 +22,7 @@ serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 thiserror = "1"
 tokio = { version = "1", features = [ "macros" ] }
-tokio-tungstenite = { version = "0.18", features = [ "rustls-tls-webpki-roots" ] }
+tokio-tungstenite = { version = "0.20", features = [ "rustls-tls-webpki-roots" ] }
 tracing = { version = "0.1", default-features = false }
 url = "2"
 uuid = { version = "1", features = [ "serde", "v4" ] }