Add convenience function to wrap a Workflow with Anyworkflow

[trevor-holliday]

Is your feature request related to a problem? Please describe.

To match the current pattern for building Workflows it would be great to be able to end the build chain with
eraseToAnyWorkflow. This would follow other modern swift paradigms (example AnyPublisher).

Describe the solution you'd like

Create an extension method on Workflow that will return the current Workflow erased as AnyWorkflow

Describe alternatives you've considered

N/A

Additional context

N/A

[Tyler Thompson]

It certainly aligns with other concepts like Combine's eraseToAnyPublisher(). I also wonder if there's some version of this that makes sense with SwiftUI tests, since SwiftUI workflows tend to get really complex type information.

This is probably a low-priority addition, but PRs are welcome!