DEV: Remove the transpilation message (#23998)

lib/tasks/assets.rake

@@ -310,8 +310,7 @@ task "assets:precompile:compress_js": "environment" do
 end
 
 task "assets:precompile:theme_transpiler": "environment" do
-  path = DiscourseJsProcessor::Transpiler.build_theme_transpiler
-  puts "Compiled theme-transpiler: #{path}"
+  DiscourseJsProcessor::Transpiler.build_theme_transpiler
 end
 
 # Run these tasks **before** Rails' "assets:precompile" task

spec/tasks/assets_precompile_spec.rb

@@ -8,10 +8,9 @@ RSpec.describe "assets:precompile" do
 
   describe "assets:precompile:theme_transpiler" do
     it "compiles the js processor" do
-      out = capture_stdout { Rake::Task["assets:precompile:theme_transpiler"].invoke }
+      path = Rake::Task["assets:precompile:theme_transpiler"].actions.first.call
 
-      expect(out).to match(%r{Compiled theme-transpiler: tmp/theme-transpiler})
-      path = out.match(/: (.+)/)[1]
+      expect(path).to match(%r{tmp/theme-transpiler})
       expect(File.exist?(path)).to eq(true)
     end
   end