Update dependency rubocop to v1.64.0

Gemfile

@@ -26,8 +26,8 @@ gem 'application_insights', git: 'https://github.com/microsoft/ApplicationInsigh
 # Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
 gem 'turbolinks', '~> 5.2'
 
-# Use puma as the app server
-gem 'puma', '~> 6.3'
+# Use iodine as the app server
+gem 'iodine', '~> 0.7'
 
 # Use null db adapter for the form objects
 gem 'activerecord-nulldb-adapter', '~> 1.0'
@@ -50,7 +50,7 @@ group :development, :test do
   gem 'bundler-audit', '~> 0.9.1'
   gem 'capybara', '~> 3.34'
   gem 'factory_bot_rails', '~> 6.2'
-  gem 'gov_fake_notify', '~> 2.0'
+  gem 'gov_fake_notify', '~> 1.1', '>= 1.1.1'
   gem 'launchy'
   gem 'listen', '~> 3.7'
   gem 'pry-rails', '~> 0.3'
@@ -79,6 +79,7 @@ group :test do
   gem 'selenium-webdriver', '~> 4.3',  '< 4.11'
   gem 'rails-controller-testing', '~> 1.0'
   gem 'climate_control', '~> 1.0'
+  gem 'puma', '~> 6.3'
   gem 'et_test_helpers', git: 'https://github.com/hmcts/et_test_helpers.git', tag: 'v1.3.2'
 end
 
@@ -109,7 +110,7 @@ gem 'uk_postcode', '~> 2.1'
 gem 'email_validator', '~> 2.2'
 gem 'typhoeus', '~> 1.4'
 gem 'invisible_captcha', '~> 2.0'
-gem 'et_gds_design_system', git:'https://github.com/hmcts/et_gds_design_system.git', tag: 'v6.0.1'
+gem 'et_gds_design_system', git:'https://github.com/hmcts/et_gds_design_system.git', tag: 'v5.4.3'
 
 gem "webpacker", "~> 5.4"
 gem "devise", "~> 4.8"

Gemfile.lock

@@ -23,12 +23,12 @@ GIT
 
 GIT
   remote: https://github.com/hmcts/et_gds_design_system.git
-  revision: 26e73f991ec226d72c67e45f750de6e17d7f5e76
-  tag: v6.0.1
+  revision: ac9718c6bc3f3573c9f515985d113815403394cb
+  tag: v5.4.3
   specs:
-    et_gds_design_system (6.0.1)
-      govuk_design_system_formbuilder (~> 5.3.0)
-      rack
+    et_gds_design_system (5.4.3)
+      govuk_design_system_formbuilder (~> 4.0)
+      rack (< 3.0.0)
       rails (>= 6.0)
       typhoeus (~> 1.4)
       webpacker (~> 5.0)
@@ -247,15 +247,15 @@ GEM
     formtastic_i18n (0.7.0)
     globalid (1.2.1)
       activesupport (>= 6.1)
-    gov_fake_notify (2.0.0)
+    gov_fake_notify (1.2.0)
       activemodel (>= 6.1)
+      iodine (~> 0.7)
       jwt (~> 2.2, >= 2.2.3)
       mail (~> 2.7, >= 2.7.1)
-      puma (~> 6.4)
       roda (~> 3.48)
       thor (~> 1.1)
       tilt (~> 2.0, >= 2.0.10)
-    govuk_design_system_formbuilder (5.3.0)
+    govuk_design_system_formbuilder (4.1.1)
       actionview (>= 6.1)
       activemodel (>= 6.1)
       activesupport (>= 6.1)
@@ -276,6 +276,7 @@ GEM
     invisible_captcha (2.3.0)
       rails (>= 5.2)
     io-console (0.7.2)
+    iodine (0.7.58)
     irb (1.12.0)
       rdoc
       reline (>= 0.4.2)
@@ -333,8 +334,6 @@ GEM
     net-smtp (0.4.0.1)
       net-protocol
     nio4r (2.7.1)
-    nokogiri (1.16.3-arm64-darwin)
-      racc (~> 1.4)
     nokogiri (1.16.3-x86_64-linux)
       racc (~> 1.4)
     notifications-ruby-client (5.4.0)
@@ -456,7 +455,7 @@ GEM
     rspec-support (3.13.1)
     rspec_junit_formatter (0.6.0)
       rspec-core (>= 2, < 4, != 2.12.0)
-    rubocop (1.63.0)
+    rubocop (1.64.0)
       json (~> 2.3)
       language_server-protocol (>= 3.17.0)
       parallel (~> 1.10)
@@ -574,7 +573,6 @@ GEM
     zeitwerk (2.6.13)
 
 PLATFORMS
-  arm64-darwin-22
   x86_64-linux
 
 DEPENDENCIES
@@ -603,10 +601,11 @@ DEPENDENCIES
   et_gds_design_system!
   et_test_helpers!
   factory_bot_rails (~> 6.2)
-  gov_fake_notify (~> 2.0)
+  gov_fake_notify (~> 1.1, >= 1.1.1)
   govuk_notify_rails!
   i18n (~> 1.14.0)
   invisible_captcha (~> 2.0)
+  iodine (~> 0.7)
   jbuilder (~> 2.10)
   jquery-rails (~> 4.4)
   launchy