Function schedule_step 

pub async fn schedule_step(
    run_id: RunId,
    step_dsl: &Step,
    executor: &mut PgConnection,
    nats_client: Client,
    hcl_ctx: &Context<'_>,
    pool: PgPool,
    workflow: &Workflow,
) -> Result<()>

Schedules a step for execution, creating a new instance and managing its initial state transitions based on dependencies and quotas.