disable puma pidfile

config/puma.rb

@@ -24,7 +24,7 @@ port ENV.fetch('PORT', 3000)
 environment ENV.fetch('RAILS_ENV', 'development')
 
 # Specifies the `pidfile` that Puma will use.
-pidfile ENV.fetch('PIDFILE', "#{Dir.tmpdir}/server.pid")
+@options[:pidfile] = false
 
 # Specifies the number of `workers` to boot in clustered mode.
 # Workers are forked web server processes. If using threads and workers together