[Rebase] Rebase to vllm 0.28.0 (#6606)

Signed-off-by: tzhouam <tzhouam@connect.ust.hk>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/worker/test_gpu_ar_model_runner.py

@@ -1,3 +1,6 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM-Omni project
+
 import asyncio
 import copy
 import re
@@ -894,6 +897,7 @@ def test_sample_tokens_tail_only_prefix_cache_uses_staged_cpu_hidden_states(monk
         lambda *args, **kwargs: (
             0,
             None,
+            None,
             [],
             None,
             ["r1", "r2"],