[Fix rubocop#12571] Fix false posives for Naming/BlockForwarding

Fixes rubocop#12571.

This PR fixes false positives for `Naming/BlockForwarding`
when using explicit block forwarding in block method.

lib/rubocop/cop/naming/block_forwarding.rb

@@ -51,21 +51,29 @@ def self.autocorrect_incompatible_with
           [Lint::AmbiguousOperator, Style::ArgumentsForwarding]
         end
 
+        # rubocop:disable Metrics/CyclomaticComplexity
         def on_def(node)
           return if node.arguments.empty?
 
           last_argument = node.last_argument
           return if expected_block_forwarding_style?(node, last_argument)
 
-          register_offense(last_argument, node)
-
+          invalid_syntax = false
           node.each_descendant(:block_pass) do |block_pass_node|
             next if block_pass_node.children.first&.sym_type? ||
                     last_argument.source != block_pass_node.source
 
+            if block_pass_node.each_ancestor(:block, :numblock).any?
+              invalid_syntax = true
+              next
+            end
+
             register_offense(block_pass_node, node)
           end
+
+          register_offense(last_argument, node) unless invalid_syntax
         end
+        # rubocop:enable Metrics/CyclomaticComplexity
         alias on_defs on_def
 
         private

spec/rubocop/cop/naming/block_forwarding_spec.rb

@@ -183,6 +183,53 @@ def foo(k: v, &block)
         RUBY
       end
 
+      it 'does not register an offense when using explicit block forwarding in block method' do
+        # Prevents the following syntax error:
+        #
+        # # foo.rb
+        # def foo(&)
+        #   block_method do
+        #     bar(&)
+        #   end
+        # end
+        #
+        # $ ruby -vc foo.rb
+        # ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [x86_64-darwin22]
+        # foo.rb: foo.rb:4: anonymous block parameter is also used within block (SyntaxError)
+        #
+        expect_no_offenses(<<~RUBY)
+          def foo(&block)
+            block_method do
+              bar(&block)
+            end
+          end
+        RUBY
+      end
+
+      it 'does not register an offense when using explicit block forwarding in numbered block method' do
+        # Prevents the following syntax error:
+        #
+        # # foo.rb
+        # def foo(&)
+        #   block_method do
+        #     bar(&)
+        #   end
+        # end
+        #
+        # $ ruby -vc foo.rb
+        # ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [x86_64-darwin22]
+        # foo.rb: foo.rb:4: anonymous block parameter is also used within block (SyntaxError)
+        #
+        expect_no_offenses(<<~RUBY)
+          def foo(&block)
+            block_method do
+              bar(&block)
+              baz(_1)
+            end
+          end
+        RUBY
+      end
+
       it 'does not register an offense when defining no arguments method' do
         expect_no_offenses(<<~RUBY)
           def foo