PersistentState and IPersistentState require to reference Microsoft.Orleans.Runtime

Hi!

I am creating an assembly with grains: `MyProject.Grains` and according to the documentation (see [Migration Guide](https://learn.microsoft.com/en-us/dotnet/orleans/migration-guide), [Tutorial](https://learn.microsoft.com/en-us/dotnet/orleans/tutorials-and-samples/tutorial-1)) I am referenceing only `Microsoft.Orleans.Sdk`.

But `PersistentState` and `IPersistentState` force me to reference `Microsoft.Orleans.Runtime` too.

Is it all right?

Start by comparing the Migration Guide and Tutorial instructions with the references required by PersistentState and IPersistentState. Confirm whether Microsoft.Orleans.Runtime is expected, then document the correct dependency guidance or identify the package-reference mismatch; done when the documented assembly references match actual compilation requirements.

Written by the indexing model from the issue text.