Fix CI build failures: clippy violations, PyO3 compatibility, and observability tests

Author: vcjana

aws/rust-runtime/Cargo.lock

@@ -59,6 +59,9 @@ tokio = { version = "1.23.1", features = ["macros", "rt", "time"] }
 tracing-subscriber = { version = "0.3.17", features = ["env-filter"] }
 tracing-test = "0.2.4"
 
+[target.'cfg(all(not(target_arch = "powerpc"), not(target_family = "wasm")))'.dev-dependencies]
+opentelemetry_sdk = { version = "0.27.1", features = ["metrics"] }
+
 [package.metadata.docs.rs]
 all-features = true
 targets = ["x86_64-unknown-linux-gnu"]