Bump pg_search from 2.0.1 to 2.3.0

Using pg_search 2.0.1 with Rails 5.2 results in deprecation warnings:

DEPRECATION WARNING: Dangerous query method (method whose arguments used
as raw SQL) called with non-attribute argument(s):
"pg_search_978c2f8941354cf552831b.rank DESC, \"tags\".\"id\" ASC".
Non-attribute arguments will be disallowed in Rails 6.0. This method
should not be called with user-provided values, such as request
parameters or model attributes. Known-safe values can be passed by
wrapping them in Arel.sql().

We're not upgrading to the latest pg_search because it only supports
ActiveRecord >= 5.2.

Gemfile

@@ -40,7 +40,7 @@ gem "omniauth-twitter", "~> 1.4.0"
 gem "paperclip", "~> 5.2.1"
 gem "paranoia", "~> 2.4.2"
 gem "pg", "~> 0.21.0"
-gem "pg_search", "~> 2.0.1"
+gem "pg_search", "~> 2.3.0"
 gem "puma", "~> 4.3.5"
 gem "recipient_interceptor", "~> 0.2.0"
 gem "redcarpet", "~> 3.4.0"

Gemfile.lock

@@ -396,10 +396,9 @@ GEM
     parser (2.7.1.3)
       ast (~> 2.4.0)
     pg (0.21.0)
-    pg_search (2.0.1)
+    pg_search (2.3.0)
       activerecord (>= 4.2)
       activesupport (>= 4.2)
-      arel (>= 6)
     public_suffix (4.0.1)
     puma (4.3.5)
       nio4r (~> 2.0)
@@ -665,7 +664,7 @@ DEPENDENCIES
   paperclip (~> 5.2.1)
   paranoia (~> 2.4.2)
   pg (~> 0.21.0)
-  pg_search (~> 2.0.1)
+  pg_search (~> 2.3.0)
   puma (~> 4.3.5)
   rails (= 5.1.7)
   rails-assets-leaflet!

app/models/concerns/searchable.rb

@@ -2,7 +2,7 @@ module Searchable
   extend ActiveSupport::Concern
 
   included do
-    include PgSearch
+    include PgSearch::Model
     include SearchCache
 
     pg_search_scope :pg_search, ->(query) do

config/initializers/acts_as_taggable_on.rb

@@ -40,7 +40,7 @@ module ActsAsTaggableOn
             Tagging.public_for_api.distinct.pluck("taggings.tag_id"))
     end
 
-    include PgSearch
+    include PgSearch::Model
 
     pg_search_scope :pg_search, against: :name,
                                 using: {