Does an async function always need to be called with await?

It is not necessary if your logic doesn't require the result of the async call. Although not needed in your case, the documentation lists two benefits to having that warning enabled:

While this is generally not necessary, it gives two main benefits. The first one is that you won't forget to add 'await' when surrounding your code with try-catch. The second one is that having explicit 'await' helps V8 runtime to provide async stack traces