gitea: Use a defined service UID

The default of 1000 mapped to my admin user, which was both a bit
concerning and a bit of an annoyance.

configuration/services/gitea.nix

@@ -1,6 +1,15 @@
 { config, ... }:
 
 {
+  users = {
+    extraUsers.gitea = {
+      isSystemUser = true;
+      description = "Gitea Service";
+      group = config.users.extraGroups.gitea.name;
+    };
+    extraGroups.gitea = { };
+  };
+
   virtualisation.pods.gitea = {
     hostname = "gitea.tlater.net";
     publish = [ "3000:3000" "2221:2221" ];
@@ -18,6 +27,9 @@
           DB_USER = "gitea";
           DB_PASSWD = "/qNDDK9WCMuubfA7D8DFwfl9T+Gy2IMDvPhiNpcxZjY=";
 
+          USER_UID = toString config.users.extraUsers.gitea.uid;
+          USER_GID = toString config.users.extraGroups.gitea.gid;
+
           RUN_MODE = "prod";
           DOMAIN = "gitea.tlater.net";
           SSH_PORT = "2221";