vulkan_library: Common::DynamicLibrary::Open is [[nodiscard]]

Ignore the return value on __APPLE__ systems as well

src/video_core/vulkan_common/vulkan_library.cpp

@@ -20,7 +20,7 @@ Common::DynamicLibrary OpenLibrary() {
         // Use the libvulkan.dylib from the application bundle.
         const std::string filename =
             Common::FS::GetBundleDirectory() + "/Contents/Frameworks/libvulkan.dylib";
-        library.Open(filename.c_str());
+        void(library.Open(filename.c_str()));
     }
 #else
     std::string filename = Common::DynamicLibrary::GetVersionedFilename("vulkan", 1);