macOS: Remove machinery for attaching NSToolBar to QWindow

It was only used by QMacToolBar in QtMacExtras, which no longer exists
in Qt 6. Attaching a toolbar can be done manually via the NSWindow of
the NSView retrieved from winId(). There are no public uses of the native
interface in GitHub outside of Qt.

Improvements we want to make to toolbars in QtWidgets and QtQuick in the
future, possibly backed by native toolbars, would be done behind the
scenes and would not need this API.

This effectively reverts e8fd6b9604bac334404dc52daa63b9e6d9cd71d8.

Pick-to: 6.5
Change-Id: I33b090fa19f9f3af029ae8c269efcf739a4b1b22
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

0 files changed, 0 insertions, 0 deletions