Ensure no tag leakage since registry is global

test/unit/block_unit_test.rb

@@ -46,6 +46,8 @@ class BlockUnitTest < Minitest::Test
   def test_with_custom_tag
     Liquid::Template.register_tag("testtag", Block)
     assert Liquid::Template.parse("{% testtag %} {% endtesttag %}")
+  ensure
+    Liquid::Template.tags.delete('testtag')
   end
 
   private

test/unit/template_unit_test.rb

@@ -72,5 +72,7 @@ class TemplateUnitTest < Minitest::Test
     Template.register_tag('fake', FakeTag)
     result = Template.tags.map { |name, klass| [name, klass] }
     assert result.include?(["fake", "TemplateUnitTest::FakeTag"])
+  ensure
+    Template.tags.delete('fake')
   end
 end