[Bug] Should wait for plugins to gracefully shutdown

[Impa10r]

Issue and Steps to Reproduce

Hi, peerswap plugin subscribes to shutdown event to shut down gracefully, but it appears that lightningd does not wait 30 seconds:

sep 24 12:43:56 vlad-VirtualBox systemd[1]: Started Core Lightning daemon.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: Stopping Core Lightning daemon...
sep 24 12:44:53 vlad-VirtualBox lightningd[584546]: Lost connection to the RPC socket.
sep 24 12:44:53 vlad-VirtualBox lightningd[584550]: Lost connection to the RPC socket.
sep 24 12:44:53 vlad-VirtualBox lightningd[584549]: Lost connection to the RPC socket.
sep 24 12:44:53 vlad-VirtualBox lightningd[584548]: Lost connection to the RPC socket.
sep 24 12:44:53 vlad-VirtualBox lightningd[584539]: Lost connection to the RPC socket.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Deactivated successfully.
sep 24 12:44:53 vlad-VirtualBox lightningd[584538]: Lost connection to the RPC socket.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Unit process 584536 (chanbackup) remains running after unit stopped.
sep 24 12:44:53 vlad-VirtualBox lightningd[584547]: Lost connection to the RPC socket.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Unit process 584540 (topology) remains running after unit stopped.
sep 24 12:44:53 vlad-VirtualBox lightningd[584543]: Lost connection to the RPC socket.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Unit process 584542 (offers) remains running after unit stopped.
sep 24 12:44:53 vlad-VirtualBox lightningd[584535]: Lost connection to the RPC socket.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Unit process 584544 (recklessrpc) remains running after unit stopped.
sep 24 12:44:53 vlad-VirtualBox lightningd[584541]: Lost connection to the RPC socket.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Unit process 584545 (recover) remains running after unit stopped.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Unit process 584547 (cln-renepay) remains running after unit stopped.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Unit process 584552 (bookkeeper) remains running after unit stopped.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Unit process 584556 (peerswap) remains running after unit stopped.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Unit process 584557 (psweb) remains running after unit stopped.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Unit process 584808 (lightning_conne) remains running after unit stopped.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Unit process 584928 (lightning_gossi) remains running after unit stopped.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: Stopped Core Lightning daemon.
sep 24 12:44:53 vlad-VirtualBox systemd[1]: lightningd.service: Consumed 29.391s CPU time.
sep 24 12:44:53 vlad-VirtualBox lightningd[584536]: Lost connection to the RPC socket.

getinfo output

v24.08.1

[wtogami]

Thanks for finding this!