Title Bar Dragging Issue in Qt6 on macOS

Description:

When using Qt6, if set `window.titlebarAppearsTransparent = YES` and 
`window.styleMask = window.styleMask | NSWindowStyleMaskFullSizeContentView` to QNSWindow. the window is NOT draggable as expected.
 
Findings:

• using AppKit and sets `titlebarAppearsTransparent = YES` and adds `NSWindowStyleMaskFullSizeContentView` to the NSWindow‘s styleMask. In this setup, the title bar is draggable.
• In Qt5, the same settings work correctly, and the title bar is draggable.
• In Qt6, however, the title bar is not draggable despite having the same configurations.
   
  Expected Behavior:
  The title bar should be draggable, allowing the user to move the window around.
   
  Actual Behavior:
  The title bar is not draggable in Qt6, even though it works as intended in Qt5.
   
  Additional Information:
  a demo project that reproduces this issue is attached.
  window-dragging-issue.zip
   
  Thank you for your attention to this matter.