message: Update BREAKING.md
  The APIs were deprecated previously (with a breaking.md warning), but the API removal PR from earlier did not include another breaking.md entry for the actual removal.
diff: ## 0.44 Breaking changes
  - [Property removed from ContainerRuntime class](#Property-removed-from-the-ContainerRuntime-class)
  - [attach() should only be called once](#attach-should-only-be-called-once)
  +- [Loader access in data stores is removed](#loader-access-in-data-stores-is-removed)
  ### Property removed from the ContainerRuntime class
  - the `existing` property from `ContainerRuntime` has been removed. Inspecting this property in order to decide whether or not to perform initialization operations should be replaced with extending the `RuntimeFactoryHelper` abstract class from `@fluidframework/runtime-utils` and overriding `instantiateFirstTime` and `instantiateFromExisting`. Alternatively, any class implementing `IRuntimeFactory` can supply an `existing` parameter to the `instantiateRuntime` method.
  ### attach() should only be called once
  `Container.attach()` will now throw if called more than once. Once called, it is responsible for retrying on retriable errors or closing the container on non-retriable errors.
  +### Loader access in data stores is removed
  +Following the deprecation warning [Loader in data stores deprecated](#loader-in-data-stores-deprecated), the associated APIs have now been removed. In addition to the original deprecation notes, users will automatically have an `ILoader` available on the container scope object as the `ILoader` property if the container was created through a `Loader`.
  +
  ## 0.43 Breaking changes
  - [TinyliciousClient and FrsClient are no longer static](#TinyliciousClient-and-FrsClient-are-no-longer-static)
  