[v0.11.0][Perf] Eliminating the zerolike operator through patch (#3632)

### What this PR does / why we need it?
There is a zero-like operator before the attention operation in each
decoding stage. After analysis, this operator can be eliminated. The
purpose of this PR is to remove this operator and improve performance.

---------

Signed-off-by: ZYang6263 <zy626375@gmail.com>

vllm_ascend/torchair/torchair_mla.py

@@ -1098,7 +1098,7 @@ class AscendMLATorchairImpl(MLAAttentionImpl):
         assert output is not None, "Output tensor must be provided."
         if attn_metadata is None:
             # Profiling run.
-            return output
+            return output.fill_(0)
         self.running_in_graph = self.torchair_graph_enabled and attn_metadata.attn_state in [
             AscendAttentionState.DecodeOnly, AscendAttentionState.SpecDecoding
         ]