Allow disabling tracing feature (#857)

Without this PR, the `tracing` in the `lambda_runtime_api_client` is not really optional, when that crate is added to the dep tree by the main `lambda_runtime` crate.

Author: yotamofek

lambda-runtime/Cargo.toml

@@ -36,7 +36,7 @@ hyper-util = { workspace = true, features = [
     "http1",
     "tokio",
 ] }
-lambda_runtime_api_client = { version = "0.11", path = "../lambda-runtime-api-client" }
+lambda_runtime_api_client = { version = "0.11", path = "../lambda-runtime-api-client", default-features = false }
 pin-project = "1"
 serde = { version = "1", features = ["derive", "rc"] }
 serde_json = "^1"