Update on "[ET-VK][AOT][ez] Introduce vulkan export utils lib"

## Changes

As title. Introduce a common Python utility library for scripts in the Vulkan backend.

Differential Revision: [D65291064](https://our.internmc.facebook.com/intern/diff/D65291064/)

[ghstack-poisoned]

Author: SS-JIA

backends/vulkan/_passes/insert_prepack_nodes.py

@@ -56,9 +56,9 @@ def prepack_not_required(node: torch.fx.Node) -> bool:
             )
             # This pass assumes that the SpecPropPass() has already been applied
             assert "spec" in node.meta
-            assert node.meta["spec"].const
             # Validate that the original node is marked as a constant. Constant tensors
             # do not participate in memory planning.
+            assert node.meta["spec"].const
             prepack_node.meta["val"] = node.meta["val"]
             prepack_node.meta["spec"] = deepcopy(node.meta["spec"])
             # Set the mem_obj_id to -1 to indicate that this node requires a dedicated