Rate limit requests from bots on Gitea

For now this is 240 r/m (4r/s), for Claude, Sogou and Meta user agents.
The values are pretty conservative, I initially had tighter limits.
Let's see how it goes, this is running on Fornax and Draco and right now
we're not hitting the limits.

site-cookbooks/kosmos_gitea/templates/default/nginx_conf_web.erb

@@ -20,6 +20,9 @@ server {
 
   proxy_intercept_errors on;
 
+  # Rate limit for bots. Defined in /etc/openresty/conf.d/rate_limits.conf
+  limit_req zone=bots burst=10; # allow a larger spike for asset bursts
+
   location ~ ^/(avatars|repo-avatars)/.*$ {
     proxy_buffers 1024 8k;
     proxy_pass http://_gitea_web;