rails: update framework files and settings to 7.0.

* Update framework files with `bin/rails app:update`.
* Update to use new Rails 7.0 default settings, except for a couple
  things regarding new cookie and cache formats that would prevent us
  from rolling back to Rails 6.1 if necessary.

bin/setup

@@ -2,7 +2,7 @@
 require "fileutils"
 
 # path to your application root.
-APP_ROOT = File.expand_path('..', __dir__)
+APP_ROOT = File.expand_path("..", __dir__)
 
 def system!(*args)
   system(*args) || abort("\n== Command #{args} failed ==")
@@ -13,24 +13,21 @@ FileUtils.chdir APP_ROOT do
   # This script is idempotent, so that you can run it at any time and get an expectable outcome.
   # Add necessary setup steps to this file.
 
-  puts '== Installing dependencies =='
-  system! 'gem install bundler --conservative'
-  system('bundle check') || system!('bundle install')
-
-  # Install JavaScript dependencies
-  system! 'bin/yarn'
+  puts "== Installing dependencies =="
+  system! "gem install bundler --conservative"
+  system("bundle check") || system!("bundle install")
 
   # puts "\n== Copying sample files =="
-  # unless File.exist?('config/database.yml')
-  #   FileUtils.cp 'config/database.yml.sample', 'config/database.yml'
+  # unless File.exist?("config/database.yml")
+  #   FileUtils.cp "config/database.yml.sample", "config/database.yml"
   # end
 
   puts "\n== Preparing database =="
-  system! 'bin/rails db:prepare'
+  system! "bin/rails db:prepare"
 
   puts "\n== Removing old logs and tempfiles =="
-  system! 'bin/rails log:clear tmp:clear'
+  system! "bin/rails log:clear tmp:clear"
 
   puts "\n== Restarting application server =="
-  system! 'bin/rails restart'
+  system! "bin/rails restart"
 end