Remove deep copy of aws-lambda-cpp

We have a deep copy of aws-lambda-cpp in this repo here: https://github.com/aws/aws-lambda-java-libs/tree/main/aws-lambda-java-runtime-interface-client/src/main/jni/deps, let's aim to remove it and use the source of truth here: https://github.com/awslabs/aws-lambda-cpp
We might need to adjust the building process