Fix vulkan dynamic library name for MacOS (#5974)
The vulkan dynamic library name is libvulkan.dylib in macos platform.
diff --git a/iree/hal/vulkan/dynamic_symbols.cc b/iree/hal/vulkan/dynamic_symbols.cc
index 8a4fe46..f8b22e2 100644
--- a/iree/hal/vulkan/dynamic_symbols.cc
+++ b/iree/hal/vulkan/dynamic_symbols.cc
@@ -69,6 +69,8 @@
static const char* kVulkanLoaderSearchNames[] = {
#if defined(IREE_PLATFORM_ANDROID)
"libvulkan.so",
+#elif defined(IREE_PLATFORM_IOS) || defined(IREE_PLATFORM_MACOS)
+ "libvulkan.dylib",
#elif defined(IREE_PLATFORM_WINDOWS)
"vulkan-1.dll",
#else