rename isTrigger to restart-on-upgrade

we're moving away from "trigger" services to "controller" services,
and "restart-on-upgrade" is the name used by s6-rc

pkgs/liminix-tools/services/default.nix

@@ -38,15 +38,15 @@ let
     , dependencies ? []
     , contents ? []
     , buildInputs ? []
-    , isTrigger ? false
+    , restart-on-upgrade ? false
     , controller ? null
   } @ args:
     stdenvNoCC.mkDerivation {
       # we use stdenvNoCC to avoid generating derivations with names
       # like foo.service-mips-linux-musl
       inherit name serviceType up down run finish notification-fd
-        producer-for consumer-for pipeline-name timeout-up timeout-down;
-      restart-on-upgrade = isTrigger;
+        producer-for consumer-for pipeline-name timeout-up timeout-down
+        restart-on-upgrade;
       buildInputs = buildInputs ++ dependencies ++ contents ++ lib.optional (controller != null) controller;
       inherit controller dependencies contents;
       builder = ./builder.sh;