NoAliveException not moved to new namespace

The new major version 8.0.0 provides a new Namespace for Eceptions: `Elastic\ElasticSearch\Exception`.

I found an Exception, which is missed move to the new namespace in `Incides`-Endpoint: https://github.com/elastic/elasticsearch-php/blob/8.0/src/Endpoints/Indices.php#L23

```php
use Elastic\Transport\Exception\NoAliveException;
```