Akka.Discovery 1.4.18-beta

Maintenance Release for Akka.NET 1.4** This is a minor release of Akka.NET that redesigns how the `Props` class and Akka.DependencyInjection uses it. _These changes are non-breaking_, but please let us know if you run into any trouble at all. [Akka: `Props` methods for propagating and setting `IActorProducer` are pretty weird](https://github.com/akkadotnet/akka.net/issues/3599) [Akka: made `Deploy` methods virtual](https://github.com/akkadotnet/akka.net/pull/4868) [Akka.DependencyInjection: `ServiceProviderProps` is broken - needs to be rewritten](https://github.com/akkadotnet/akka.net/issues/4853) [Akka.Streams: FileIO sinks don't flush until completed](https://github.com/akkadotnet/akka.net/issues/4851) To see the [full set of fixes in Akka.NET v1.4.18, please see the milestone on Github](https://github.com/akkadotnet/akka.net/milestone/48). | COMMITS | LOC+ | LOC- | AUTHOR | | --- | --- | --- | --- | | 3 | 431 | 451 | Aaron Stannard | | 3 | 229 | 4980 | Gregorius Soedharmo | | 2 | 2 | 2 | dependabot-preview[bot] |