Fix rubocop linter errors

Gemfile

@@ -1,18 +1,18 @@
-source "https://rubygems.org"
+source 'https://rubygems.org'
 git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
 gem 'rubocop', '>= 1.0', '< 2.0'
 
-ruby "3.2.2"
+ruby '3.2.2'
 
 # Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
-gem "rails", "~> 7.0.5"
+gem 'rails', '~> 7.0.5'
 
 # Use postgresql as the database for Active Record
-gem "pg", "~> 1.1"
+gem 'pg', '~> 1.1'
 
 # Use the Puma web server [https://github.com/puma/puma]
-gem "puma", "~> 5.0"
+gem 'puma', '~> 5.0'
 
 # Build JSON APIs with ease [https://github.com/rails/jbuilder]
 # gem "jbuilder"
@@ -27,10 +27,10 @@ gem "puma", "~> 5.0"
 # gem "bcrypt", "~> 3.1.7"
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
-gem "tzinfo-data", platforms: %i[ mingw mswin x64_mingw jruby ]
+gem 'tzinfo-data', platforms: %i[mingw mswin x64_mingw jruby]
 
 # Reduces boot times through caching; required in config/boot.rb
-gem "bootsnap", require: false
+gem 'bootsnap', require: false
 
 # Use Active Storage variants [https://guides.rubyonrails.org/active_storage_overview.html#transforming-images]
 # gem "image_processing", "~> 1.2"
@@ -40,11 +40,10 @@ gem "bootsnap", require: false
 
 group :development, :test do
   # See https://guides.rubyonrails.org/debugging_rails_applications.html#debugging-with-the-debug-gem
-  gem "debug", platforms: %i[ mri mingw x64_mingw ]
+  gem 'debug', platforms: %i[mri mingw x64_mingw]
 end
 
 group :development do
   # Speed up commands on slow machines / big apps [https://github.com/rails/spring]
   # gem "spring"
 end
-

app/mailers/application_mailer.rb

@@ -1,4 +1,4 @@
 class ApplicationMailer < ActionMailer::Base
-  default from: "[email protected]"
-  layout "mailer"
+  default from: '[email protected]'
+  layout 'mailer'
 end

config.ru

@@ -1,6 +1,6 @@
 # This file is used by Rack-based servers to start the application.
 
-require_relative "config/environment"
+require_relative 'config/environment'
 
 run Rails.application
 Rails.application.load_server

test/channels/application_cable/connection_test.rb

@@ -1,4 +1,4 @@
-require "test_helper"
+require 'test_helper'
 
 class ApplicationCable::ConnectionTest < ActionCable::Connection::TestCase
   # test "connects with cookies" do

test/test_helper.rb

@@ -1,6 +1,6 @@
-ENV["RAILS_ENV"] ||= "test"
-require_relative "../config/environment"
-require "rails/test_help"
+ENV['RAILS_ENV'] ||= 'test'
+require_relative '../config/environment'
+require 'rails/test_help'
 
 class ActiveSupport::TestCase
   # Run tests in parallel with specified workers