Rename with_error_mode(...) to with_error_modes(...)

test/integration/context_test.rb

@@ -632,7 +632,7 @@ class ContextTest < Minitest::Test
   end
 
   def test_has_key_will_not_add_an_error_for_missing_keys
-    with_error_mode(:strict) do
+    with_error_modes(:strict) do
       context = Context.new
       context.key?('unknown')
       assert_empty(context.errors)