feat(sterni/machines/ingeborg): disallow crawling of /tmp

Change-Id: Ic104ff7837c5f728b4e9b33b2ed2ed1ceba8103e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/13054
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI

users/sterni/machines/ingeborg/http/sterni.lv.nix

@@ -28,6 +28,12 @@ in
       };
       # TODO(sterni): tmp.sterni.lv
       locations."/tmp/".root = toString /srv/http;
+      extraConfig = ''
+        location = /robots.txt {
+           add_header Content-Type text/plain;
+           return 200 "User-agent: *\nDisallow: /tmp\n";
+        }
+      '';
     };
   };
 }