Fix missing CA::MetalLayer declaration in BabylonNative.h

Include QuartzCore/CAMetalLayer.h explicitly so that CA::MetalLayer
is declared when BabylonNative.h is compiled. MTKView.h alone does
not guarantee the CA namespace is available in all build contexts
(e.g. the CI runner with Xcode 26).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: CedricGuillemet

Modules/@babylonjs/react-native/shared/BabylonNative.h

@@ -4,6 +4,7 @@
 
 #if defined(__APPLE__)
 #include <MetalKit/MTKView.h>
+#include <QuartzCore/CAMetalLayer.h>
 #elif defined(ANDROID)
 #include <android/native_window.h>
 #elif WINAPI_FAMILY == WINAPI_FAMILY_APP