Swift 6 error: "Sending '$....$generator' risks causing data races"

[vanvoorden (Rick van Voorden)]

Use `withThrowingTaskGroup` within Actor leads to `Non-sendable type '(inout ThrowingTaskGroup<Void, any Error>) async throws -> ()'` compilation warning

The fix is a combination of very recent changes, I don't expect it to be in beta 2 but we expect this error to go away in subsequent releases. I can't comment on exact release dates though, sorry about that.

It also looks like it might be a known issue on task groups (not just a known issue on any arbitrary async sequence).