macOS: Remove warning about KVO observers on QNSWindow/QNSPanel

NSTitleBarView in Big Sur will observe the window it is in, but makes
sure to remove these observers in viewWillMoveToWindow, as it should.
To avoid spamming user logs with this warning we remove it.

It was dubious what cases it would have caught anyways, as anyone
trying to KVO observe properties Z of a child object Y of X.Y would
need to track whether X changes its Y between adding and removing
the observer. There are no guarantees that Y is stable, and this
applies to an NSView's window property as well.

Pick-to: 6.0
Pick-to: 5.15
Pick-to: 5.12
Change-Id: I27a0d04625f96c4c5d382c39ac068721ce1e8f9d
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

0 files changed, 0 insertions, 0 deletions