[CI] Fix UT failure (#2563)

UT is broken by vLLM commit
https://github.com/vllm-project/vllm/pull/23664

This PR mock the related config to recover the CI

- vLLM version: v0.10.1.1
- vLLM main:
6dab89b8ec

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>

tests/ut/core/test_scheduler.py

@@ -135,6 +135,8 @@ class TestAscendScheduler(TestBase):
         )
         model_config.pooler_config = MagicMock()
         model_config.multimodal_config = MagicMock()
+        model_config.hf_config = MagicMock()
+        model_config.hf_config.is_encoder_decoder = False
         # Cache config, optionally force APC
         kwargs_cache: Dict[str,
                            Any] = ({} if ENABLE_PREFIX_CACHING is None else {