Add const keyward to Node::isScheduled and Scheduler::isScheduled (#17833)

Author: Atsumu Ono

cocos/base/CCScheduler.cpp

@@ -500,7 +500,7 @@ void Scheduler::schedulePerFrame(const ccSchedulerFunc& callback, void *target,
     }
 }
 
-bool Scheduler::isScheduled(const std::string& key, void *target)
+bool Scheduler::isScheduled(const std::string& key, void *target) const
 {
     CCASSERT(!key.empty(), "Argument key must not be empty");
     CCASSERT(target, "Argument target must be non-nullptr");
@@ -1003,7 +1003,7 @@ void Scheduler::schedule(SEL_SCHEDULE selector, Ref *target, float interval, boo
     this->schedule(selector, target, interval, CC_REPEAT_FOREVER, 0.0f, paused);
 }
 
-bool Scheduler::isScheduled(SEL_SCHEDULE selector, Ref *target)
+bool Scheduler::isScheduled(SEL_SCHEDULE selector, Ref *target) const
 {
     CCASSERT(selector, "Argument selector must be non-nullptr");
     CCASSERT(target, "Argument target must be non-nullptr");

cocos/base/CCScheduler.h

@@ -363,15 +363,15 @@ class CC_DLL Scheduler : public Ref
      @return True if the specified callback is invoked, false if not.
      @since v3.0.0
      */
-    bool isScheduled(const std::string& key, void *target);
+    bool isScheduled(const std::string& key, void *target) const;
 
     /** Checks whether a selector for a given target is scheduled.
      @param selector The selector to be checked.
      @param target The target of the callback.
      @return True if the specified selector is invoked, false if not.
      @since v3.0
      */
-    bool isScheduled(SEL_SCHEDULE selector, Ref *target);
+    bool isScheduled(SEL_SCHEDULE selector, Ref *target) const;
 
     /////////////////////////////////////