Merge pull request #30614 from kami-zh/yarn-on-bin-update

Align `bin/update`'s Yarn usage with `bin/setup`

railties/lib/rails/generators/rails/app/templates/bin/update.tt

@@ -15,6 +15,11 @@ chdir APP_ROOT do
   puts '== Installing dependencies =='
   system! 'gem install bundler --conservative'
   system('bundle check') || system!('bundle install')
+<% unless options.skip_yarn? -%>
+
+  # Install JavaScript dependencies if using Yarn
+  # system('bin/yarn')
+<% end -%>
 <% unless options.skip_active_record? -%>
 
   puts "\n== Updating database =="