hydra: bayfront: Stop serving nars through bayfront.guix.gnu.org.

This is partially duplicating the behaviour of the NGinx configuration
for bordeaux.guix.gnu.org. For maintainability, I think it's worth now
switching to just having bordeaux.guix.gnu.org serve nars. This also
enables getting guix publish back running on bayfront.guix.gnu.org if
that's something that's wanted.

* hydra/bayfront.scm (%bayfront.guix.gnu.org-nginx-servers): Remove
substitute serving related configuration.

hydra/bayfront.scm

@@ -442,43 +442,10 @@ proxy_set_header X-Forwarded-For  $proxy_add_x_forwarded_for;"))
 (define %bayfront.guix.gnu.org-nginx-servers
   (let ((common-locations
          (list
-          (nginx-location-configuration
-           (uri "= /nix-cache-info")
-           (body '("
-    return 200 'StoreDir: /gnu/store\nWantMassQuery: 0\nPriority: 100\n';
-    add_header Content-Type text/plain;")))
           (nginx-location-configuration
            (uri "= /404")
-           (body '("
-return 404 '404';
-add_header Content-Type text/plain;")))
-          (nginx-location-configuration
-           (uri "~ \\.narinfo$")
-           (body '("
-    root /var/lib/nars;
-
-    error_page 404 /404;
-
-    # For HTTP pipelining.  This has a dramatic impact on performance.
-    client_body_buffer_size 128k;
-
-    # Narinfos requests are short, serve many of them on a connection.
-    keepalive_requests 20000;
-
-    add_header Content-Type text/plain;
-")))
-          (nginx-location-configuration
-           (uri "/nar/")
-           (body '("
-    root /var/lib/nars;
-
-    error_page 404 /404;
-
-    client_body_buffer_size 256k;
-
-    # Nars are already compressed.
-    gzip off;
-"))))))
+           (body '("return 404 '404';"
+                   "add_header Content-Type text/plain;"))))))
 
     (list
      (nginx-server-configuration