[CI] Upgrade vLLM to 20250919 (6d8246aa) and fix some broken issue (#2907)

### What this PR does / why we need it?
1. This pr bump vllm commit to
6d8246aaff
2. fix upstream changes https://github.com/vllm-project/vllm/pull/24548
abort multi-modal kwargs, make vllm main and `v0.10.2` both adaptable
3. fix metadata_builder changes introduced by
https://github.com/vllm-project/vllm/pull/23693
4. fix `structured_outputs_config` changes introduced by
https://github.com/vllm-project/vllm/pull/22772
5. fix `moe_config` changes introduced by
https://github.com/vllm-project/vllm/pull/22537

Co-authored-by:  MengqingCao <cmq0113@163.com>
Co-authored-by:  Yikun Jiang <yikunkero@gmail.com>


- vLLM version: v0.10.2
- vLLM main:
c60e6137f0

---------

Signed-off-by: wangli <wangli858794774@gmail.com>
Signed-off-by: MengqingCao <cmq0113@163.com>
Co-authored-by: MengqingCao <cmq0113@163.com>

vllm_ascend/quantization/quant_config.py

@@ -404,6 +404,10 @@ class AscendFusedMoEMethod(FusedMoEMethodBase):
         if hasattr(self.quant_method, "process_weights_after_loading"):
             self.quant_method.process_weights_after_loading(layer)
 
+    def get_fused_moe_quant_config(self, layer: torch.nn.Module):
+        # TODO: implement this function
+        pass
+
 
 class AscendEmbeddingMethod(AscendLinearMethod):
     """Embedding method for Ascend quantization.