Remove empty finalizers

Whenever you can, avoid finalizers because of the additional performance overhead that's involved in tracking object lifetime. The garbage collector runs the finalizer before it collects the object. This means that at least two collections are required to collect the object. An empty finalizer incurs this added overhead without any benefit.

A type implements a finalizer that is empty, calls only the base type finalizer, or calls only conditionally emitted methods.

Remove the empty finalizer. If a finalizer is required for debugging, enclose the whole finalizer in #if DEBUG / #endif directives.

Do not suppress a message from this rule.