clean 0.15.0 support (#6852)

Clean up vllm 0.15.0 related code

- vLLM version: v0.16.0
- vLLM main:
15d76f74e2

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

vllm_ascend/_310p/fused_moe/fused_moe.py

@@ -153,11 +153,10 @@ class AscendFusedMoE310(FusedMoE):
         self.quant_type = self.get_quant_type()
 
         _MoECommMethods[MoECommType.ALLGATHER] = AllGatherCommImpl310(self.moe_config)
-
-        if not vllm_version_is("0.15.0"):
+        if not vllm_version_is("0.16.0"):
             self.runner = self._init_runner()
 
-    if not vllm_version_is("0.15.0"):
+    if not vllm_version_is("0.16.0"):
 
         def _init_runner(self):
             from vllm_ascend.ops.fused_moe.fused_moe import AscendMoERunner