Upgrade sb library to latest version

Use latest version of azure-servicebus. We are seeing an intermittent issue with delete subscription workflow where the client connection for the deleted subscription is not being properly closed. The connection close action happens here for Notification service. The issue we see that the client connection is still open (thus, message pump still being attempted; a lot of exception entries from this) even after close is "successful" (logger info can be seen in Appinsights logs). This is causing an explosion in exception logs, making it expensive. This upgrade hopefully fixes the issue with client connection closing.

We are also working on creating a support ticket with MSFT about the issue and another Gitlab issue to migrate to the suggested SB library.