[Elasticsearch] Remove elasticsearch-model gem

This should be the bulk of the work to integrate with opensearch-ruby

Gemfile

@@ -29,7 +29,7 @@ gem 'sidekiq-unique-jobs'
 gem 'redis'
 gem 'request_store'
 
-gem 'elasticsearch-model'
+gem 'elasticsearch'
 
 gem 'mailgun-ruby'
 gem 'resolv'

Gemfile.lock

@@ -130,10 +130,6 @@ GEM
       elasticsearch-transport (= 7.17.7)
     elasticsearch-api (7.17.7)
       multi_json
-    elasticsearch-model (7.2.1)
-      activesupport (> 3)
-      elasticsearch (~> 7)
-      hashie
     elasticsearch-transport (7.17.7)
       faraday (~> 1)
       multi_json
@@ -172,7 +168,6 @@ GEM
     globalid (1.1.0)
       activesupport (>= 5.0)
     hashdiff (1.0.1)
-    hashie (5.0.0)
     http-accept (1.7.0)
     http-cookie (1.0.5)
       domain_name (~> 0.5)
@@ -406,7 +401,7 @@ DEPENDENCIES
   dotenv-rails
   draper
   dtext_rb!
-  elasticsearch-model
+  elasticsearch
   factory_bot_rails
   httparty
   listen

app/indexes/indexable.rb

@@ -1,12 +0,0 @@
-# frozen_string_literal: true
-
-# Base Elasticsearch indexing definitions
-#
-# Make sure to include your custom index file
-# in your model alongside Indexable.
-module Indexable
-  def self.included(base)
-    base.include Elasticsearch::Model
-    base.include DocumentStore::Model
-  end
-end

app/models/post.rb

@@ -1644,7 +1644,7 @@ class Post < ApplicationRecord
   include ValidationMethods
   include PostEventMethods
   include Danbooru::HasBitFlags
-  include Indexable
+  include DocumentStore::Model
   include PostIndex
 
   BOOLEAN_ATTRIBUTES = %w(

app/models/post_version.rb

@@ -119,7 +119,7 @@ class PostVersion < ApplicationRecord
   end
 
   extend SearchMethods
-  include Indexable
+  include DocumentStore::Model
   include PostVersionIndex
 
   def self.queue(post)

config/initializers/elasticsearch.rb

@@ -1 +0,0 @@
-Elasticsearch::Model.client = Elasticsearch::Client.new host: Danbooru.config.elasticsearch_host