This needs significant work to use the new Metal→Vulkan integration
extension `VK_EXT_metal_objects`
```
MoltenVK/mvk_deprecated_api.h:132:1: note: 'vkGetMTLDeviceMVK' has been explicitly marked deprecated here
MVK_DEPRECATED_USE_MTL_OBJS
^
MoltenVK/mvk_deprecated_api.h:74:52: note: expanded from macro 'MVK_DEPRECATED_USE_MTL_OBJS'
#define MVK_DEPRECATED_USE_MTL_OBJS VKAPI_ATTR [[deprecated("Use the VK_EXT_metal_objects extension instead.")]]
^
../sys/applemedia/videotexturecache-vulkan.mm:303:20: error: 'vkSetMTLTextureMVK' is deprecated:
Use the VK_EXT_metal_objects extension instead.
VkResult err = vkSetMTLTextureMVK (memory->vulkan_mem.image, texture);
^
MoltenVK/mvk_deprecated_api.h:151:1: note: 'vkSetMTLTextureMVK' has been explicitly marked deprecated here
MVK_DEPRECATED_USE_MTL_OBJS
^
MoltenVK/mvk_deprecated_api.h:74:52: note: expanded from macro 'MVK_DEPRECATED_USE_MTL_OBJS'
#define MVK_DEPRECATED_USE_MTL_OBJS VKAPI_ATTR [[deprecated("Use the VK_EXT_metal_objects extension instead.")]]
^
2 errors generated.
```
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7091>