chore: Enable the new Rubocop rules (#7122)

fixes: https://linear.app/chatwoot/issue/CW-1574/renable-the-disabled-rubocop-rules

spec/helpers/cache_keys_helper_spec.rb

@@ -1,6 +1,6 @@
 require 'rails_helper'
 
-RSpec.describe CacheKeysHelper, type: :helper do
+RSpec.describe CacheKeysHelper do
   let(:account_id) { 1 }
   let(:key) { 'example_key' }
 

spec/helpers/email_helper_spec.rb

@@ -1,6 +1,6 @@
 require 'rails_helper'
 
-describe EmailHelper, type: :helper do
+describe EmailHelper do
   describe '#normalize_email_with_plus_addressing' do
     context 'when email is passed' do
       it 'normalise if plus addressing is present' do

spec/helpers/frontend_urls_helper_spec.rb

@@ -1,6 +1,6 @@
 require 'rails_helper'
 
-describe FrontendUrlsHelper, type: :helper do
+describe FrontendUrlsHelper do
   describe '#frontend_url' do
     context 'without query params' do
       it 'creates path correctly' do

spec/helpers/message_format_helper_spec.rb

@@ -1,6 +1,6 @@
 require 'rails_helper'
 
-describe MessageFormatHelper, type: :helper do
+describe MessageFormatHelper do
   describe '#transform_user_mention_content' do
     context 'when transform_user_mention_content called' do
       it 'return transormed text correctly' do

spec/helpers/url_helper_spec.rb

@@ -1,6 +1,6 @@
 require 'rails_helper'
 
-describe UrlHelper, type: :helper do
+describe UrlHelper do
   describe '#url_valid' do
     context 'when url valid called' do
       it 'return if valid url passed' do