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/e2e/nightly/multi_node/config/models/DeepSeek-V3.yaml

@@ -82,7 +82,6 @@ deployment:
         --trust-remote-code
         --no-enable-prefix-caching
         --gpu-memory-utilization 0.9
-        --additional-config '{"torchair_graph_config":{"enabled":true}}'
         --kv-transfer-config
         '{"kv_connector": "MooncakeConnector",
         "kv_role": "kv_consumer",