dry-run is broken when module is using iterable return type

```
./vendor/bin/codecept dry-run Acceptance

In DryRun.php line 194:

  Unsupported return type iterable


dry-run <suite> [<test>]
```


It's because of `iterable` return type, in my case the one specified at https://github.com/Codeception/lib-innerbrowser/blob/74476dd019ec7900b26b7dca91a42fdcb04e549f/src/Codeception/Lib/InnerBrowser.php#L127