[Bug] Fix `error 'Dynamo failed to run FX node with fake tensors` for Deepseek V3.2 (#31046)

Signed-off-by: yewentao256 <zhyanwentao@126.com>

vllm/model_executor/models/deepseek_v2.py

@@ -878,8 +878,11 @@ class Indexer(nn.Module):
         )
 
         q_pe, k_pe = rotary_emb(positions, q_pe, k_pe.unsqueeze(1))
-        q = torch.cat([q_pe.squeeze(0), q_nope], dim=-1)
-        k = torch.cat([k_pe.squeeze((0, 2)), k_nope], dim=-1)
+        # `rotary_emb` is shape-preserving; `q_pe` is already
+        # [num_tokens, n_head, rope_dim].
+        q = torch.cat([q_pe, q_nope], dim=-1)
+        # `k_pe` is [num_tokens, 1, rope_dim] (MQA).
+        k = torch.cat([k_pe.squeeze(1), k_nope], dim=-1)
 
         # we only quant q here since k quant is fused with cache insertion
         q = q.view(-1, self.head_dim)