Actress post release fixes

@pitr-ch I just discovered that this line causes the global_task_pool Delay to evaluate. This makes it impossible to explicitly configure the global task pool. This code will fail with `Concurrent::ConfigurationError: global task pool was already set`:

```ruby
require 'concurrent'

Concurrent.configure do |config|
  config.global_task_pool = Concurrent::CachedThreadPool.new
end
```

I'm not sure if there is anything that can be done about this, but could you please look into it?