ServiceEndPointResolver.GetEndPointsAsync not work with net.tcp scheme

Package: Microsoft.Extentions.ServiceDiscovery 8 preview 5

I would like to use the ServiceDiscovery library to be able to retrieve the Endpoint of a WCF service with net.tcp protocol.

But this code return null:

```cs
var endPointResolver = serviceProvider.GetRequiredService();
var result = await endPointResolver.GetEndPointAsync("net.tcp://basket", default).ConfigureAwait(false);
Assert.IsNull(result);
```

Configuration appSettings.json:

```json
{
"Services": {
"basket": {
"net.tcp": "net.tcp://localhost:82378"
}
}
}
```