bug(odin+agenix): set nullmailer user as owner

hosts/odin/age.nix

@@ -1,11 +1,13 @@
-{ inputs, ... }:
+{ config, inputs, ... }:
 {
   imports = [ inputs.agenix.nixosModules.default ];
 
   age.identityPaths = [ "/persist/etc/ssh/ssh_host_ed25519_key" ];
   age.secrets = {
-    "odin/nullmailer/remotes".file =
-      inputs.secrets."odin/nullmailer/remotes";
+    "odin/nullmailer/remotes" = {
+      file = inputs.secrets."odin/nullmailer/remotes";
+      owner = config.services.nullmailer.user;
+    };
     "odin/thomas".file = inputs.secrets."odin/thomas";
   };
 }