New comment by dkwo on void-packages repository

https://github.com/void-linux/void-packages/pull/46165#issuecomment-1894637024

Comment:
- remove the postrm hook, which does not work
- we currently install (and also in my prior pr) /usr/lib/kernel/install.d/91-sbctl.install, but this is arch/systemd specific, so remove it