We will at some point need to handle DESTROY messages in the relay circuit reactor. When we implement this, we should ensure that the destroy reason is not propagated in any outgoing DESTROY cells. We should use `END_REASON_CIRCUIT_DESTROYED` instead. See the comments at https://gitlab.torproject.org/tpo/core/arti/-/work_items/2466#note_3394014. /cc @gabi-250 @dgoulet