[vulkan] Fix python overrides tests for is_vulkan_available (#39016)

Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/39016

Differential Revision: D21724619

Pulled By: IvanKobzarev

fbshipit-source-id: d7a6c8b944a55bc4f2cce957eeac08c5801667a0
diff --git a/torch/_overrides.py b/torch/_overrides.py
index c2542d9..cacd014 100644
--- a/torch/_overrides.py
+++ b/torch/_overrides.py
@@ -139,6 +139,7 @@
         torch.autocast_increment_nesting,
         torch.autocast_decrement_nesting,
         torch.nn.functional.hardswish,
+        torch.is_vulkan_available,
     )
 
 def get_testing_overrides():