fix: configure gitea to use correct ssh port

nixos/server/default.nix

@@ -48,7 +48,6 @@
       PasswordAuthentication = false;
       KbdInteractiveAuthentication = false;
       PermitRootLogin = "no";
-      AllowUsers = [ "leonhard" ];
     };
   };
 

nixos/server/gitea.nix

@@ -10,6 +10,7 @@ in
   services.gitea = {
     enable = true;
     settings.server.ROOT_URL = "https://${gitDomain}";
+    settings.server.SSH_PORT = builtins.elemAt config.services.openssh.ports 0;
     settings.service.DISABLE_REGISTRATION = true;
     settings.log.LEVEL = "Critical";
   };