Reduce exceptions thrown in Aspire.Hosting

[JamesNK]

Exceptions thrown in the app host are always printed to the debug console. Althrough the errors are handled, they add noise the debug console. For example, #7486

Common exceptions:

• k8s.Autorest throws HttpOperationException in many situations. For example, GetAsync for a resource that doesn't exist throws the error. I'm not sure what options there are to suppress them.
• OperationCanceledException is thrown from many canceled async operations. For example, canceling watching for resource notifications. ConfigureAwaitOptions.NoThrow could be used to stop them. Or gracefully completing channels when we no longer want to read from them instead of aborting read with a cancellation token.