function headerMiddleware(shim, config, next) {
  return async function wrappedHeaderMw(args) {
    // this is an indicator in the agent http-outbound instrumentation
    // to disable DT from AWS requests as they are not necessary
    args.request.headers['x-new-relic-disable-dt'] = 'true'
    return await next(args)
  }
}
Wraps the build middleware step to add the disable DT
header to all outgoing requests

@param {Shim} shim
@param config
@param {function} next next function in middleware chain
@returns {function}