`evaluate_promise` has nothing to do with `promises`

It seems the goal of `evaluate_promise` is to group `expect_output`,  `expect_warning`,  `expect_message`. It does not seem to handle code that returns promises:

MRE:

```r
test_that("it does not handle promises", {
  expect_snapshot(
    evaluate_promise(
      promises::promise_resolve(42)
    )
  )
})
```

```
...
Output
  $result
  <Promise [pending]>
...
```