CI: Test with ruby 3.0 as the latest ruby version

Refactor render_layout method for serialization

.github/workflows/liquid.yml

@@ -6,9 +6,8 @@ jobs:
     strategy:
       matrix:
         entry:
-          - { ruby: 2.5, allowed-failure: false }
-          - { ruby: 2.6, allowed-failure: false }
-          - { ruby: 2.7, allowed-failure: false }
+          - { ruby: 2.5, allowed-failure: false } # minimum supported
+          - { ruby: 3.0, allowed-failure: false } # latest
           - { ruby: ruby-head, allowed-failure: true }
     name: test (${{ matrix.entry.ruby }})
     steps:

performance/theme_runner.rb

@@ -73,10 +73,14 @@ class ThemeRunner
 
   private
 
+  def render_layout(template, layout, assigns)
+    assigns['content_for_layout'] = template.render!(assigns)
+    layout&.render!(assigns)
+  end
+
   def compile_and_render(template, layout, assigns, page_template, template_file)
-    compiled_test                 = compile_test(template, layout, assigns, page_template, template_file)
-    assigns['content_for_layout'] = compiled_test[:tmpl].render!(assigns)
-    compiled_test[:layout].render!(assigns) if layout
+    compiled_test = compile_test(template, layout, assigns, page_template, template_file)
+    render_layout(compiled_test[:tmpl], compiled_test[:layout], compiled_test[:assigns])
   end
 
   def compile_all_tests

test/integration/context_test.rb

@@ -461,6 +461,7 @@ class ContextTest < Minitest::Test
   end
 
   def test_interrupt_avoids_object_allocations
+    @context.interrupt? # ruby 3.0.0 allocates on the first call
     assert_no_object_allocations do
       @context.interrupt?
     end