Is the errorListener method disposed after the CachedNetworkImage is disposed?

## 💬 Questions and Help

I'm implementing a custom logging mechanism when the image loading fails. I found the errorListener really useful to get that info, but after some performance testing I noticed the callback from `errorListener` gets called even if the `CachedNetworkImage` widget gets disposed.

I took a look at the code and wasn't able to find a place where the method `removeListener` was used, except from [testing files](https://github.com/Baseflow/flutter_cached_network_image/blob/develop/cached_network_image/test/image_stream_completer_test.dart#L120).

I'm asking this, because it seems like the regular `Image.network` widget from Flutter does call the `removeListener` method. If the method is not being called in this package, is there any reason to not do it? Is it safe from memory leaks?

Thanks!