regression on -current with qt5-webkit

qt5-webkit doesn't build anymore on -current, see the errors bellow:
-----------------------
/tmp/qtwebkit-5.212.0-alpha4/Source/WTF/wtf/glib/GRefPtr.h:33:21: error: expected ')' before 'typename'
33 | extern "C" gpointer g_object_ref_sink(gpointer);
| ^~~~~~~~~~~~~~~~~
In file included from /usr/include/glib-2.0/gobject/gbinding.h:29,
from /usr/include/glib-2.0/glib-object.h:22,
from /usr/include/gstreamer-1.0/gst/gstenumtypes.h:6,
from /usr/include/gstreamer-1.0/gst/gst.h:31,
from /tmp/qtwebkit-5.212.0-alpha4/Source/WebCore/platform/graphics/gstreamer/GStreamerUtilities.h:21,
from /tmp/qtwebkit-5.212.0-alpha4/Source/WebCore/platform/graphics/gstreamer/GStreamerUtilities.cpp:23:
/tmp/qtwebkit-5.212.0-alpha4/Source/WTF/wtf/glib/GRefPtr.h:33:21: note: to match this '('
33 | extern "C" gpointer g_object_ref_sink(gpointer);
| ^~~~~~~~~~~~~~~~~
/tmp/qtwebkit-5.212.0-alpha4/Source/WebCore/platform/graphics/gstreamer/GStreamerUtilities.cpp: In function 'GstClockTime WebCore::toGstClockTime(float)':
/tmp/qtwebkit-5.212.0-alpha4/Source/WebCore/platform/graphics/gstreamer/GStreamerUtilities.cpp:183:14: warning: 'GTimeVal' is deprecated: Use 'GDateTime' instead [-Wdeprecated-declarations]
183 | GTimeVal timeValue;
| ^~~~~~~~~
In file included from /usr/include/glib-2.0/glib/galloca.h:32,
from /usr/include/glib-2.0/glib.h:30,
from /usr/include/gstreamer-1.0/gst/gst.h:27,
from /tmp/qtwebkit-5.212.0-alpha4/Source/WebCore/platform/graphics/gstreamer/GStreamerUtilities.h:21,
from /tmp/qtwebkit-5.212.0-alpha4/Source/WebCore/platform/graphics/gstreamer/GStreamerUtilities.cpp:23:
/usr/include/glib-2.0/glib/gtypes.h:545:26: note: declared here
545 | typedef struct _GTimeVal GTimeVal GLIB_DEPRECATED_TYPE_IN_2_62_FOR(GDateTime);
| ^~~~~~~~
make[2]: *** [Source/WebCore/CMakeFiles/WebCore.dir/build.make:28984: Source/WebCore/CMakeFiles/WebCore.dir/platform/graphics/gstreamer/GStreamerUtilities.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:1509: Source/WebCore/CMakeFiles/WebCore.dir/all] Error 2
make: *** [Makefile:166: all] Error 2
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