drone: ensure docker starts before trying to

create docker network drone-net with systemd dependencies

hosts/flora-6/drone.nix

@@ -31,12 +31,16 @@
     "d '/var/lib/drone-db' 0750 drone drone - -"
   ];
 
-  system.activationScripts.mkDroneNet = let
+  systemd.services."docker-network-drone" = let
     docker = config.virtualisation.oci-containers.backend;
     dockerBin = "${pkgs.${docker}}/bin/${docker}";
-  in ''
+  in {
+    serviceConfig.Type = "oneshot";
+    before = ["docker-drone-server.service"];
+    script = ''
       ${dockerBin} network inspect drone-net >/dev/null 2>&1 || ${dockerBin} network create drone-net --subnet 172.20.0.0/24
     '';
+  };
 
   virtualisation = {
     docker = {