DEV: Drop workbox dependency (#26735)

This service-worker caching functionality was disabled by default in 1c58395bca, and the setting to re-enable was marked as experimental. Now we are dropping all the related logic.

lib/ember_cli.rb

@@ -46,15 +46,6 @@ class EmberCli < ActiveSupport::CurrentAttributes
       end
   end
 
-  def self.workbox_dir_name
-    return @workbox_base_dir if defined?(@workbox_base_dir)
-
-    @workbox_base_dir =
-      if (full_path = Dir.glob("app/assets/javascripts/discourse/dist/assets/workbox-*")[0])
-        File.basename(full_path)
-      end
-  end
-
   def self.has_tests?
     File.exist?("#{dist_dir}/tests/index.html")
   end

lib/freedom_patches/sprockets_patches.rb

@@ -54,8 +54,6 @@ Sprockets::DirectiveProcessor.prepend(
 Sprockets::Asset.prepend(
   Module.new do
     def digest_path
-      # Workbox assets are already in a folder with a digest in the name
-      return logical_path if logical_path.start_with?("workbox-")
       # Webpack chunks are already named based on their contents
       return logical_path if logical_path.start_with?("chunk.")
       super

lib/tasks/assets.rake

@@ -267,7 +267,6 @@ task "assets:precompile:compress_js": "environment" do
         manifest
           .files
           .select { |k, v| k =~ /\.js\z/ }
-          .reject { |k, v| k =~ %r{/workbox-.*'/} }
           .each do |file, info|
             path = "#{assets_path}/#{file}"
             _file =