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.

spec/components/validators/password_validator_spec.rb

@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 require 'rails_helper'
-require_dependency "common_passwords/common_passwords"
 
 describe PasswordValidator do
 

spec/components/validators/post_validator_spec.rb

@@ -1,12 +1,11 @@
 # frozen_string_literal: true
 
 require 'rails_helper'
-require_dependency 'validators/post_validator'
 
-describe Validators::PostValidator do
+describe PostValidator do
   fab!(:topic) { Fabricate(:topic) }
   let(:post) { build(:post, topic: topic) }
-  let(:validator) { Validators::PostValidator.new({}) }
+  let(:validator) { PostValidator.new({}) }
 
   context "#post_body_validator" do
     it 'should not allow a post with an empty raw' do
@@ -16,7 +15,7 @@ describe Validators::PostValidator do
     end
 
     context "when empty raw can bypass validation" do
-      let(:validator) { Validators::PostValidator.new(skip_post_body: true) }
+      let(:validator) { PostValidator.new(skip_post_body: true) }
 
       it "should be allowed for empty raw based on site setting" do
         post.raw = ""

spec/components/validators/upload_validator_spec.rb

@@ -1,9 +1,8 @@
 # frozen_string_literal: true
 
 require 'rails_helper'
-require_dependency 'validators/upload_validator'
 
-describe Validators::UploadValidator do
+describe UploadValidator do
   subject(:validator) { described_class.new }
 
   describe 'validate' do