When we attach a `ViewRef` to a `ViewContainerRef`, we save a reference to the container
onto the `ViewRef` so that we can remove it when the ref is destroyed. The problem is
that if the container's `hostView` is destroyed first, the `ViewRef` has no way of knowing
that it should stop referencing the container.
These changes remove the leak by not saving a reference at all. Instead, when a `ViewRef`
is destroyed, we clean it up through the `LContainer` directly. We don't need to worry
about the case where the container is destroyed before the view, because containers
automatically clean up all of their views upon destruction.
Fixes#38648.
PR Close#40219