[Fix #12746] Fix a false positive for Lint/ToEnumArguments

Fixes #12746.

This PR fixes a false positive for `Lint/ToEnumArguments`
when enumerator is created for another method in no arguments method definition.

changelog/fix_a_false_positive_for_lint_to_enum_arguments.md

@@ -0,0 +1 @@
+* [#12746](https://github.com/rubocop/rubocop/pull/12746): Fix a false positive for `Lint/ToEnumArguments` when enumerator is created for another method in no arguments method definition. ([@koic][])

lib/rubocop/cop/lint/to_enum_arguments.rb

@@ -51,8 +51,13 @@ def on_send(node)
           enum_conversion_call?(node) do |method_node, arguments|
             next if method_node.call_type? &&
                     !method_node.method?(:__method__) && !method_node.method?(:__callee__)
-            next if method_name?(method_node, def_node.method_name) &&
-                    arguments_match?(arguments, def_node)
+
+            valid = if method_name?(method_node, def_node.method_name)
+                      arguments_match?(arguments, def_node)
+                    else
+                      def_node.arguments.empty?
+                    end
+            return if valid
 
             add_offense(node)
           end

spec/rubocop/cop/lint/to_enum_arguments_spec.rb

@@ -113,6 +113,14 @@ def m(x)
     RUBY
   end
 
+  it 'does not register an offense when enumerator is created for another method in no arguments method definition' do
+    expect_no_offenses(<<~RUBY)
+      def m
+        return to_enum(:not_m) unless block_given?
+      end
+    RUBY
+  end
+
   it 'registers an offense when enumerator is created for `__method__` with missing arguments' do
     expect_offense(<<~RUBY)
       def m(x)