Startup work and enqueued work that defines a new transaction scope can restore a completed ambient transaction

[rars]

Reproduction:

var actor = CreateActor(ActorCreateOptions.None);
await actor.Start();

var result = await actor.Enqueue(async () =>
            {
                using (var scope = new TransactionScope(TransactionScopeOption.Suppress, TransactionScopeAsyncFlowOption.Enabled))
                {
                    await Task.Delay(200);
                } // Restores ambient transaction which should be null

                if (Transaction.Current != null) /* <-- this line will actually fail because the ambient transaction that's restored is marked as completed so throws an InvalidOperationException */
                {
                    Console.WriteLine("Ambient transaction found!");
                }

                return 1;
            });

[rars]

I have a fix for this that I will push shortly.

[rars]

Released in 1.8.0