[Maintenance] Add `--end-after-restart` option

[Jackenmen]

I always forget to disable maintenance after bot restart and usually, that's when I want it to end so here's a PR adding this functionality...

Is it tested? Actually yes.

[Jackenmen]

After using maintenance for a while, I feel this would actually be more useful if you could set the amount of time that needs to pass after bot restart until maintenance is disabled.