Remove redundant default member initializer from DelayNode

Fixes clang-tidy warning cppcoreguidelines-use-default-member-init.
Now matches the pattern used by TimeoutNode: no default in header,
explicit initialization in both constructors.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: facontidavide

include/behaviortree_cpp/decorators/delay_node.h

@@ -67,7 +67,7 @@ class DelayNode : public DecoratorNode
   std::atomic_bool delay_complete_ = false;
   bool delay_aborted_ = false;
   unsigned msec_;
-  bool read_parameter_from_ports_ = false;
+  bool read_parameter_from_ports_;
   std::mutex delay_mutex_;
 };