[Bugfix] JAIS: Only apply ALiBi when position_embedding_type='alibi' (#37820)

Co-authored-by: r266-tech <r266-tech@users.noreply.github.com>

vllm/model_executor/models/jais.py

@@ -117,6 +117,9 @@ class JAISAttention(nn.Module):
             prefix=f"{prefix}.c_proj",
         )
 
+        self.use_alibi = config.position_embedding_type == "alibi"
+        alibi_slopes = None
+        if self.use_alibi:
             tp_rank = get_tensor_model_parallel_rank()
             head_start = tp_rank * self.num_heads
             head_end = (tp_rank + 1) * self.num_heads