1. According to Apple Developer Documentation, @autorelease block is the preferred method over using an instance of NSAutoreleasePool directly. This is also discussed in Cocoa/highgui: fix leak in cvGetWindowRect_COCOA #26625 (comment).

2. Starting from commit 4ec4cf6, highgui_cocoa.mm contained numerous debug lines that had been commented out, such as:
   

   opencv/modules/highgui/src/window_cocoa.mm

   Lines 172 to 183 in dbb330d

   	static CVWindow *cvGetWindow(const char *name) {
   	//cout << "cvGetWindow" << endl;
   	NSAutoreleasePool* localpool = [[NSAutoreleasePool alloc] init];
   	NSString *cvname = [NSString stringWithFormat:@"%s", name];
   	CVWindow* retval = (CVWindow*) [windows valueForKey:cvname] ;
   	//cout << "retain count: " << [retval retainCount] << endl;
   	//retval = [retval retain];
   	//cout << "retain count: " << [retval retainCount] << endl;
   	[localpool drain];
   	//cout << "retain count: " << [retval retainCount] << endl;
   	return retval;
   	}

   
   Such extraneous comments should be removed once debugging is complete and should not remain in the release environment. A previous commit fb34f36 had partially cleaned up these comments. This PR made a thorough review and cleaned up the remaining extraneous comments.

Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

• I agree to contribute to the project under Apache 2 License.
• To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
• The PR is proposed to the proper branch
• There is a reference to the original bug report and related work
• There is accuracy test, performance test and test data in opencv_extra repository, if applicable
  Patch to opencv_extra has the same branch name.
• The feature is well documented and sample code can be built with the project CMake