Drop torchair (#4814)

aclgraph is stable and fast now. Let's drop torchair graph mode now.

TODO: some logic to adapt torchair should be cleaned up as well. We'll
do it in the following PR.

- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>
Co-authored-by: Mengqing Cao <cmq0113@163.com>

tests/ut/ops/test_fused_moe.py

@@ -118,7 +118,6 @@ def mock_dist_env(mocker: MockerFixture):
             return_value=mock_dp_and_tp_group(mocker)), \
         patch('vllm_ascend.ops.fused_moe.fused_moe.get_ascend_config',
             return_value=MagicMock(
-                torchair_graph_config=MagicMock(enabled=False),
                 enable_multistream_moe=False,
                 expert_map_path=None
             )), \