[Dist][EP] Remove ETP/EP maintained in vllm-ascend (#1681)

### What this PR does / why we need it?
Remove ETP/EP maintained in branch main. We drop this as there is no
relevant scenarios to use ETP now, and we may subsequently advocate
implementing expert tensor parallelism in vLLM to support scenarios
where the expert is needed to be sliced

This is a part of #1422 backport.

Fixes https://github.com/vllm-project/vllm-ascend/issues/1396
https://github.com/vllm-project/vllm-ascend/issues/1154

### Does this PR introduce _any_ user-facing change?
We'll not maintain etp/ep in vllm-ascend anymore, and use the tp/ep in
vllm instead.

### How was this patch tested?
CI passed with new added and existing test.


- vLLM version: v0.9.2
- vLLM main:
fe8a2c544a

Signed-off-by: MengqingCao <cmq0113@163.com>

vllm_ascend/worker/worker_v1.py

@@ -41,7 +41,6 @@ from vllm.v1.worker.worker_base import WorkerBase
 import vllm_ascend.envs as envs_ascend
 from vllm_ascend.ascend_config import get_ascend_config, init_ascend_config
 from vllm_ascend.device_allocator.camem import CaMemAllocator
-from vllm_ascend.distributed.parallel_state import init_ascend_model_parallel
 from vllm_ascend.platform import NPUPlatform
 from vllm_ascend.utils import (check_kv_cache_bytes_cache_exist,
                                check_torchair_cache_exist,
@@ -308,18 +307,12 @@ class NPUWorker(WorkerBase):
 
     def _init_worker_distributed_environment(self) -> None:
         """Initialize the distributed environment."""
-        parallel_config = self.vllm_config.parallel_config
         init_distributed_environment(self.parallel_config.world_size,
                                      self.rank, self.distributed_init_method,
                                      self.local_rank, "hccl")
         ensure_model_parallel_initialized(
             self.parallel_config.tensor_parallel_size,
             self.parallel_config.pipeline_parallel_size)
-        init_ascend_model_parallel(
-            parallel_config.expert_parallel_size,
-            parallel_config.expert_tensor_parallel_size,
-            parallel_config.world_size_across_dp,
-        )
         ensure_kv_transfer_initialized(self.vllm_config)
 
     def _init_profiler(self):