Update dependency paper_trail to v15

Gemfile

@@ -16,7 +16,7 @@ gem 'uglifier'
 gem 'figaro', '~> 1.2'
 
 # model related
-gem 'paper_trail', '~> 14.0'
+gem 'paper_trail', '~> 15.0'
 gem 'pg', '1.5.4'
 # 1.8 is for Rails < 5.0
 gem 'ransack', '~> 4.0.0'

Gemfile.lock

@@ -194,7 +194,7 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    concurrent-ruby (1.2.2)
+    concurrent-ruby (1.2.3)
     connection_pool (2.4.1)
     countries (4.0.1)
       i18n_data (~> 0.13.0)
@@ -310,7 +310,7 @@ GEM
       rake
     mini_mime (1.1.2)
     mini_portile2 (2.8.2)
-    minitest (5.18.1)
+    minitest (5.21.2)
     minitest-stub_any_instance (1.0.3)
     monetize (1.9.4)
       money (~> 6.12)
@@ -357,8 +357,8 @@ GEM
       validate_url
       webfinger (~> 1.2)
     orm_adapter (0.5.0)
-    paper_trail (14.0.0)
-      activerecord (>= 6.0)
+    paper_trail (15.1.0)
+      activerecord (>= 6.1)
       request_store (~> 1.4)
     pdfkit (0.8.7.2)
     pg (1.5.4)
@@ -528,7 +528,7 @@ GEM
     wkhtmltopdf-binary (0.12.6.6)
     xpath (3.2.0)
       nokogiri (~> 1.8)
-    zeitwerk (2.6.8)
+    zeitwerk (2.6.12)
 
 PLATFORMS
   ruby
@@ -575,7 +575,7 @@ DEPENDENCIES
   nokogiri (~> 1.15.0)
   omniauth-rails_csrf_protection
   omniauth-tara!
-  paper_trail (~> 14.0)
+  paper_trail (~> 15.0)
   pdfkit
   pg (= 1.5.4)
   pg_query (>= 0.9.0)