use /bin/sh for init scripts

modules/s6/scripts/rc.init

@@ -1,4 +1,4 @@
-#!/usr/bin/env sh
+#!/bin/sh
 
 rl="$1"
 shift

modules/s6/scripts/rc.shutdown

@@ -1,4 +1,4 @@
-#!/usr/bin/env sh
+#!/bin/sh
 
 
 ### Things to do before hardware halt/reboot/poweroff.

modules/s6/scripts/rc.shutdown.final

@@ -1,4 +1,4 @@
-#!/nix/store/xbdqbi2mscmhl5wcpbgpjdwxbsrvpkil-bash-5.1-p16/bin/sh -e
+#!/bin/sh -e
 
 ### Things to do *right before* the machine gets rebooted or
 ### powered off, at the very end of the shutdown sequence,

modules/s6/scripts/runlevel

@@ -1,4 +1,4 @@
-#!/usr/bin/env sh -e
+#!/bin/sh -e
 
 ### This script is called once at boot time by rc.init, and is
 ### also called by the runleveld service every time the user