* Added serde feature to remove build warnings

Author: imdexsam

rclrs/Cargo.toml

@@ -49,6 +49,7 @@ dyn_msg = ["ament_rs", "libloading"]
 # This feature is solely for the purpose of being able to generate documetation without a ROS installation
 # The only intended usage of this feature is for docs.rs builders to work, and is not intended to be used by end users
 generate_docs = ["rosidl_runtime_rs/generate_docs"]
+serde = []
 
 [package.metadata.docs.rs]
 features = ["generate_docs"]