feat: add valuable feature support to appender-tracing

Author: steved

Cargo.toml

@@ -90,6 +90,7 @@ rust_2024_compatibility = { level = "warn", priority = -1 }
 edition_2024_expr_fragment_specifier = "allow"
 if_let_rescope = "allow"
 tail_expr_drop_order = "allow"
+unexpected_cfgs = { level = "warn", check-cfg = ["cfg(tracing_unstable)"] }
 
 [workspace.lints.clippy]
 all = { level = "warn", priority = 1 }

opentelemetry-appender-log/Cargo.toml

@@ -26,7 +26,7 @@ opentelemetry-semantic-conventions = { version = "0.30", path = "../opentelemetr
 
 [features]
 spec_unstable_logs_enabled = ["opentelemetry/spec_unstable_logs_enabled"]
-with-serde = ["log/kv_serde", "serde"]
+with-serde = ["log/kv_serde", "opentelemetry/with-serde", "serde"]
 experimental_metadata_attributes = ["dep:opentelemetry-semantic-conventions"]
 
 [dev-dependencies]