The Tenant Migration Access Blocker has an executor so callers might wait on access blockers using this executor. It was added to the registry last year as the previous method had deadlock issues. However it added unintended dependencies on numerous modules as including the registry now includes the executor/network stack. As the registry is included by the service context (registry is a decoration on top of the service context) it added a network/executor dependencies in a lot of locations. We want to refactor it to remove this dependency.