bump tokio version

Author: ifsheldon

async-openai-wasm/Cargo.toml

@@ -46,4 +46,4 @@ eventsource-stream = "0.2"
 
 [dev-dependencies]
 tokio-test = "0.4"
-tokio = { version = "1.37", features = ["fs", "macros"] }
+tokio = { version = "1.38", features = ["fs", "macros"] }