DEV: Upgrading Discourse to Zeitwerk (#8098)

Zeitwerk simplifies working with dependencies in dev and makes it easier reloading class chains. 

We no longer need to use Rails "require_dependency" anywhere and instead can just use standard 
Ruby patterns to require files.

This is a far reaching change and we expect some followups here.

lib/demon/demon_base.rb

@@ -3,7 +3,7 @@
 module Demon; end
 
 # intelligent fork based demonizer
-class Demon::Base
+class Demon::DemonBase
 
   def self.demons
     @demons
@@ -57,7 +57,7 @@ class Demon::Base
   def alive?(pid = nil)
     pid ||= @pid
     if pid
-      Demon::Base.alive?(pid)
+      Demon::DemonBase.alive?(pid)
     else
       false
     end
@@ -143,7 +143,7 @@ class Demon::Base
   def already_running?
     if File.exists? pid_file
       pid = File.read(pid_file).to_i
-      if Demon::Base.alive?(pid)
+      if Demon::DemonBase.alive?(pid)
         return pid
       end
     end

lib/demon/rails_autospec.rb

@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-require "demon/base"
+require "demon/demon_base"
 
-class Demon::RailsAutospec < Demon::Base
+class Demon::RailsAutospec < Demon::DemonBase
 
   def self.prefix
     "rails-autospec"

lib/demon/sidekiq.rb

@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-require "demon/base"
+require "demon/demon_base"
 
-class Demon::Sidekiq < Demon::Base
+class Demon::Sidekiq < ::Demon::DemonBase
 
   def self.prefix
     "sidekiq"