Update on "[ET-VK][ez] Explicitly skip marking output nodes that are mutable buffers"

## Changes

* Move the logic skipping output nodes that are mutable buffers from runtime to AOT

## Context

A `fx.Graph` may return nodes that are mutable buffers:


```
    class GraphModule(torch.nn.Module):
        def forward(self, p_wrapped_module_wq_weight: "f32[2048, 2048]", p_wrapped_module_wk_weight: "f32[512, 2048]", p_wrapped_module_wv_weight: "f32[512, 2048]", p_wrapped_module_wo_weight: "f32[2048, 2048]", b_wrapped_module_kv_cache_k_cache: "f32[1, 2048, 8, 64]", b_wrapped_module_kv_cache_v_cache: "f32[1, 2048, 8, 64]", x: "f32[1, s27, 2048]", freqs_cos: "f32[s27, 32]", freqs_sin: "f32[s27, 32]", input_pos: "i64[1]"):
            sym_size: "Sym(s27)" = torch.ops.aten.sym_size.int(x, 1)

            ...

            # b_wrapped_module_kv_cache_*_cache are mutable buffers
            # getitem_2 and getitem_3 are derived from mutable buffers, hence they are
            # themselves mutable buffers
            auto_functionalized = torch.ops.higher_order.auto_functionalized(torch.ops.llama.update_cache.default, value = getitem_1, cache = b_wrapped_module_kv_cache_k_cache, start_pos = _local_scalar_dense_1);  getitem_1 = b_wrapped_module_kv_cache_k_cache = None
            getitem_2: "f32[1, 2048, 8, 64]" = auto_functionalized[1];  auto_functionalized = None
            auto_functionalized_1 = torch.ops.higher_order.auto_functionalized(torch.ops.llama.update_cache.default, value = aten_view_copy_default_8, cache = b_wrapped_module_kv_cache_v_cache, start_pos = _local_scalar_dense_1);  aten_view_copy_default_8 = b_wrapped_module_kv_cache_v_cache = _local_scalar_dense_1 = None
            getitem_3: "f32[1, 2048, 8, 64]" = auto_functionalized_1[1];  auto_functionalized_1 = None

            ...

            aten_permute_copy_default_3: "f32[2048, 2048]" = executorch_exir_dialects_edge__ops_aten_permute_copy_default(p_wrapped_module_wo_weight, [1, 0]);  p_wrapped_module_wo_weight = None
            aten_view_copy_default_10: "f32[s27, 2048]" = executorch_exir_dialects_edge__ops_aten_view_copy_default(aten_view_copy_default_9, [sym_size, 2048]);  aten_view_copy_default_9 = None
            aten_mm_default_3: "f32[s27, 2048]" = executorch_exir_dialects_edge__ops_aten_mm_default(aten_view_copy_default_10, aten_permute_copy_default_3);  aten_view_copy_default_10 = aten_permute_copy_default_3 = None
            aten_view_copy_default_11: "f32[1, s27, 2048]" = executorch_exir_dialects_edge__ops_aten_view_copy_default(aten_mm_default_3, [1, sym_size, 2048]);  aten_mm_default_3 = sym_size = None

            # getitem_2 and getitem_3 are returned as outputs, presumably to prevent the
            # update_cache calls from being removed due to dead code elimination
            return (getitem_2, getitem_3, aten_view_copy_default_11, None)
```

In the graph signature of the `ExportedProgram` these show up as `BUFFER_MUTATION` outputs

```
Graph signature:
    # inputs
    p_wrapped_module_wq_weight: PARAMETER target='wrapped_module.wq.weight'
    p_wrapped_module_wk_weight: PARAMETER target='wrapped_module.wk.weight'
    p_wrapped_module_wv_weight: PARAMETER target='wrapped_module.wv.weight'
    p_wrapped_module_wo_weight: PARAMETER target='wrapped_module.wo.weight'
    b_wrapped_module_kv_cache_k_cache: BUFFER target='wrapped_module.kv_cache.k_cache' persistent=True
    b_wrapped_module_kv_cache_v_cache: BUFFER target='wrapped_module.kv_cache.v_cache' persistent=True
    x: USER_INPUT
    freqs_cos: USER_INPUT
    freqs_sin: USER_INPUT
    input_pos: USER_INPUT

    # outputs
    getitem_2: BUFFER_MUTATION target='wrapped_module.kv_cache.k_cache'
    getitem_3: BUFFER_MUTATION target='wrapped_module.kv_cache.v_cache'
    aten_view_copy_default_11: USER_OUTPUT
    : USER_OUTPUT
```

Although these nodes are technically returned by the `fx.Graph`, `BUFFER_MUTATION` outputs are not included in the delegate call schema. Since the Vulkan delegate serialization uses the output node to mark which values are returned as outputs, this could result in a mismatch betwen the outputs of the Vulkan delegate and the outputs expected by the ExecuTorch runtime.

## Motivation

Previously, this mismatch was addressed in the runtime, by skipping the processing of non-tensor outputs. However, this solution does not account for the fact that in some models, paramters of the model may be returned as outputs. In this case, those parameter outputs would be skipped but the ExecuTorch runtime would still expect to receive them as outputs.

To solve the problem properly, this diff changes the serialization logic to check if an output node is a mutable buffer, and skip marking it as an output if so. In the runtime, all output nodes are processed instead of only processing tensor outputs.

Differential Revision: [D77281491](https://our.internmc.facebook.com/intern/diff/D77281491/)

[ghstack-poisoned]

Author: SS-JIA