Replace sassc-rails with dartsass-rails

Gemfile

@@ -4,14 +4,14 @@ gem "rails", "7.1.3.4"
 
 gem "bootsnap", require: false
 gem "bootstrap-kaminari-views"
+gem "dartsass-rails"
 gem "govuk_app_config"
 gem "hashdiff"
 gem "jquery-ui-rails"
 gem "kaminari"
 gem "pg"
 gem "prometheus-client"
 gem "rack-proxy"
-gem "sassc-rails"
 gem "select2-rails", "< 4" # There are unresolved visual and HTML changes with select2-rails 4
 gem "sentry-sidekiq"
 gem "simple_form"

Gemfile.lock

@@ -117,6 +117,9 @@ GEM
       rexml
     crass (1.0.6)
     csv (3.3.0)
+    dartsass-rails (0.5.1)
+      railties (>= 6.0.0)
+      sass-embedded (~> 1.63)
     date (3.3.4)
     diff-lcs (1.5.1)
     docile (1.4.0)
@@ -650,14 +653,17 @@ GEM
       rubocop (~> 1.61)
     ruby-progressbar (1.13.0)
     rubyzip (2.3.2)
+    sass-embedded (1.77.8)
+      google-protobuf (~> 4.26)
+      rake (>= 13)
+    sass-embedded (1.77.8-aarch64-linux-gnu)
+      google-protobuf (~> 4.26)
+    sass-embedded (1.77.8-arm64-darwin)
+      google-protobuf (~> 4.26)
+    sass-embedded (1.77.8-x86_64-linux-gnu)
+      google-protobuf (~> 4.26)
     sassc (2.4.0)
       ffi (~> 1.9)
-    sassc-rails (2.1.2)
-      railties (>= 4.0.0)
-      sassc (>= 2.0)
-      sprockets (> 3.0)
-      sprockets-rails
-      tilt
     select2-rails (3.5.11)
     selenium-webdriver (4.21.1)
       base64 (~> 0.2)
@@ -702,7 +708,6 @@ GEM
     terser (1.2.3)
       execjs (>= 0.3.0, < 3)
     thor (1.3.1)
-    tilt (2.0.10)
     timeout (0.4.1)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
@@ -742,6 +747,7 @@ DEPENDENCIES
   better_errors
   bootsnap
   bootstrap-kaminari-views
+  dartsass-rails
   factory_bot_rails
   fakefs
   gds-api-adapters
@@ -764,7 +770,6 @@ DEPENDENCIES
   rails (= 7.1.3.4)
   rspec-rails
   rubocop-govuk
-  sassc-rails
   select2-rails (< 4)
   sentry-sidekiq
   simple_form