Function send_prepared_http_step 

pub async fn send_prepared_http_step<FCancel>(
    client: &Client,
    prepared: PreparedHttpStep,
    step: &PipelineStep,
    context: &HashMap<String, StepExecutionResult>,
    specs: Option<&[RuntimeSpec]>,
    env_groups: Option<&[RuntimeEnvGroup]>,
    selected_env_group_slug: Option<&str>,
    should_cancel: FCancel,
) -> Option<StepExecutionResult>
where
    FCancel: FnMut() -> bool,