Update base for Update on "[ET-VK] Add symint infrastructure to VulkanBackend and ComputeGraph"

Extend the Vulkan backend runtime infrastructure to better support symbolic
integer (symint) arguments. This is a prerequisite for operators that need
to handle dynamic shapes via symint values.

Changes:
- VulkanBackend.cpp: Compute output offset from end of args instead of
  assuming outputs follow inputs directly. Add scalar-to-tensor input
  handling so that Int/Bool EValues can populate tensor inputs. Support
  symint inputs provided as raw Int EValues (not just scalar tensors).
  Add symint output handling to write values back as tensor or Int EValue.
- ComputeGraph.h: Add SymInt case to extract_scalar<T>() so operators
  can transparently read symint values as scalars.
- ComputeGraph.cpp: Add Int fallback in read_symint() so values stored
  as plain Int (rather than SymInt objects) can be read uniformly.

Differential Revision: [D95970167](https://our.internmc.facebook.com/intern/diff/D95970167/)

cc manuelcandales digantdesai cbilgin

[ghstack-poisoned]

Author: ssjia

backends/vulkan/_passes/tag_memory_meta_pass.py

@@ -302,7 +302,7 @@ def constrain_repset_with_user(
             current_node, arg_repset, search_depth
         )
 
-    def trace_node_users_to_constrain_repset(
+    def trace_node_users_to_constrain_repset(  # noqa: C901
         self,
         origin_node: torch.fx.Node,
         repset: utils.TensorRepSet,