qt6-qtwebengine fails to build on MacOS Sequoia

[RivetBenoit (Benoit Rivet)]

I tried to install py312-pyqt6 on Mac OS Sequoia. The installation initally failed due to a bug in orbit2, but thanks to the work of ryandesign (many thanks to him and every people working for MacPorts), orbit2 compiles fine on Sequoia. However, py312-pyqt6 now fails when trying to compile qt6-qtwebengine. The first error I spotted in the log file happens line 16754 :

:info:build FAILED: obj/ui/base/base/base_jumbo_mm.o 
(snip the overly long line 16755)
:info:build In file included from gen/ui/base/base_jumbo_mm.mm:18:
:info:build In file included from ./../../../../../qtwebengine-everywhere-src-6.7.2/src/3rdparty/chromium/ui/base/cocoa/permissions_utils.mm:14:
:info:build ../../../../../qtwebengine-everywhere-src-6.7.2/src/3rdparty/chromium/base/mac/wrap_cg_display.h:22:5: error: expected function body after function declarator
:info:build    22 |     CG_AVAILABLE_BUT_DEPRECATED(
:info:build       |     ^
:info:build In file included from gen/ui/base/base_jumbo_mm.mm:19:
:info:build In file included from ./../../../../../qtwebengine-everywhere-src-6.7.2/src/3rdparty/chromium/ui/base/cocoa/remote_accessibility_api.mm:5:
:info:build ../../../../../qtwebengine-everywhere-src-6.7.2/src/3rdparty/chromium/ui/base/cocoa/remote_accessibility_api.h:18:1: error: missing context for method declaration
:info:build    18 | + (NSData*)remoteTokenForLocalUIElement:(id)element;
:info:build       | ^
:info:build ../../../../../qtwebengine-everywhere-src-6.7.2/src/3rdparty/chromium/ui/base/cocoa/remote_accessibility_api.h:19:1: error: expected method body
:info:build    19 | - (id)initWithRemoteToken:(NSData*)token;
:info:build       | ^
:info:build ../../../../../qtwebengine-everywhere-src-6.7.2/src/3rdparty/chromium/ui/base/cocoa/remote_accessibility_api.h:20:1: error: unexpected '@' in program
:info:build    20 | @property(strong) id windowUIElement;
:info:build       | ^
:info:build ../../../../../qtwebengine-everywhere-src-6.7.2/src/3rdparty/chromium/ui/base/cocoa/remote_accessibility_api.h:21:1: error: unexpected '@' in program
:info:build    21 | @property(strong) id topLevelUIElement;
:info:build       | ^
:info:build ../../../../../qtwebengine-everywhere-src-6.7.2/src/3rdparty/chromium/ui/base/cocoa/remote_accessibility_api.h:22:1: error: '@end' must appear in an Objective-C context
(snip the rest)