Update tokio-tungstenite requirement from 0.20.0 to 0.21.0

Updates the requirements on [tokio-tungstenite](https://github.com/snapview/tokio-tungstenite) to permit the latest version.
- [Changelog](https://github.com/snapview/tokio-tungstenite/blob/master/CHANGELOG.md)
- [Commits](snapview/tokio-tungstenite@v0.20.0...v0.21.0)

---
updated-dependencies:
- dependency-name: tokio-tungstenite
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

kube-client/Cargo.toml

@@ -61,7 +61,7 @@ tokio-util = { version = "0.7.0", optional = true, features = ["io", "codec"] }
 hyper = { version = "0.14.13", optional = true, features = ["client", "http1", "stream", "tcp"] }
 hyper-rustls = { version = "0.24.0", optional = true }
 hyper-socks2 = { version = "0.8.0", optional = true, default-features = false }
-tokio-tungstenite = { version = "0.20.0", optional = true }
+tokio-tungstenite = { version = "0.21.0", optional = true }
 tower = { version = "0.4.13", optional = true, features = ["buffer", "filter", "util"] }
 tower-http = { version = "0.4.0", optional = true, features = ["auth", "map-response-body", "trace"] }
 hyper-timeout = {version = "0.4.1", optional = true }