expose pitchfork worker in env

which is helpful for logging for example worker.nr in app error handling

lib/pitchfork/http_server.rb

@@ -722,6 +722,7 @@ def process_client(client, worker, timeout_handler)
 
       proc_name status: "requests: #{worker.requests_count}, processing: #{env["PATH_INFO"]}"
 
+      env["pitchfork.worker"] = worker
       timeout_handler.rack_env = env
       env["pitchfork.timeout"] = timeout_handler