Fix a stall in running `quit` while a live process is running (#74687)

We need to generate events when finalizing, or we won't know that we
succeeded in stopping the process to detach/kill. Instead, we stall and
then after our 20 interrupt timeout, we kill the process (even if we
were supposed to detach) and exit.

OTOH, we have to not generate events when the Process is being
destructed because shared_from_this has already been torn down, and
using it will cause crashes.