dev-qt/qtbase: defer to new global USE=vulkan description

Signed-off-by: Sam James <[email protected]>

dev-qt/qtbase/metadata.xml

@@ -22,7 +22,6 @@
 		<flag name="systemd">Enable native journald logging support</flag>
 		<flag name="tslib">Enable support for touchscreen devices via <pkg>x11-libs/tslib</pkg></flag>
 		<flag name="tuio">Build plugin to receive touch events over the TUIO protocol</flag>
-		<flag name="vulkan">Enable support for Vulkan</flag>
 		<flag name="widgets">Build Qt6Widgets module</flag>
 		<flag name="X">Build the XCB platform plugin and enable X11 integration</flag>
 	</use>