[Core] Cleanup triton patch which has been fixed in vllm (#764)

### What this PR does / why we need it?
- Revert "Re-patch TritonPlaceholder on main to make CI happy (#753)"
because upstream main CI already merged:
https://github.com/vllm-project/vllm/pull/17446
- Keep 0.8.5.post1 compatible

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
CI passed

---------

Signed-off-by: Yikun Jiang <yikunkero@gmail.com>

vllm_ascend/__init__.py

@@ -23,9 +23,5 @@ def register():
 
 
 def register_model():
-    # TODO: fixme when TritonPlaceholder fixed
-    from vllm_ascend.utils import vllm_version_is
-    if not (vllm_version_is("0.8.5") or vllm_version_is("0.8.5.post1")):
-        import vllm_ascend.patch.worker.patch_main.patch_tritonplaceholder  # noqa
     from .models import register_model
     register_model()