Put chroot provision into its own preflight

install/preflight/chroot.sh

@@ -0,0 +1,12 @@
+# Chroot installations have some differences
+if ! cmp -s /proc/1/root/ / 2>/dev/null; then
+  export OMARCHY_CHROOT_INSTALL=1
+fi
+
+chrootable_systemctl_enable() {
+  if [ -n "${OMARCHY_CHROOT_INSTALL:-}" ]; then
+    sudo systemctl enable $1
+  else
+    sudo systemctl enable --now $1
+  fi
+}