[Misc] Add SPDX-License-Identifier headers to python source files (#12628)

- **Add SPDX license headers to python source files**
- **Check for SPDX headers using pre-commit**

commit 9d7ef44c3cfb72ca4c32e1c677d99259d10d4745
Author: Russell Bryant <rbryant@redhat.com>
Date:   Fri Jan 31 14:18:24 2025 -0500

    Add SPDX license headers to python source files
    
This commit adds SPDX license headers to python source files as
recommended to
the project by the Linux Foundation. These headers provide a concise way
that is
both human and machine readable for communicating license information
for each
source file. It helps avoid any ambiguity about the license of the code
and can
    also be easily used by tools to help manage license compliance.
    
The Linux Foundation runs license scans against the codebase to help
ensure
    we are in compliance with the licenses of the code we use, including
dependencies. Having these headers in place helps that tool do its job.
    
    More information can be found on the SPDX site:
    
    - https://spdx.dev/learn/handling-license-info/

Signed-off-by: Russell Bryant <rbryant@redhat.com>

commit 5a1cf1cb3b80759131c73f6a9dddebccac039dea
Author: Russell Bryant <rbryant@redhat.com>
Date:   Fri Jan 31 14:36:32 2025 -0500

    Check for SPDX headers using pre-commit
Signed-off-by: Russell Bryant <rbryant@redhat.com>

---------
Signed-off-by: Russell Bryant <rbryant@redhat.com>

tests/tpu/test_quantization_accuracy.py

+# SPDX-License-Identifier: Apache-2.0
+
 from dataclasses import dataclass
 
 import lm_eval

tests/tracing/test_tracing.py

+# SPDX-License-Identifier: Apache-2.0
+
 import os
 import threading
 from concurrent import futures

tests/utils.py

+# SPDX-License-Identifier: Apache-2.0
+
 import asyncio
 import copy
 import functools

tests/v1/core/test_kv_cache_utils.py

+# SPDX-License-Identifier: Apache-2.0
+
 import pytest
 
 from vllm.multimodal.inputs import MultiModalKwargs

tests/v1/core/test_prefix_caching.py

+# SPDX-License-Identifier: Apache-2.0
 """Compare the with and without prefix caching."""
 import pytest
 

tests/v1/e2e/test_cascade_attention.py

+# SPDX-License-Identifier: Apache-2.0
+
 from vllm import LLM, SamplingParams
 
 

tests/v1/engine/test_async_llm.py

+# SPDX-License-Identifier: Apache-2.0
+
 import asyncio
 from contextlib import ExitStack
 from typing import List, Tuple

tests/v1/engine/test_engine_args.py

+# SPDX-License-Identifier: Apache-2.0
+
 import pytest
 
 from vllm import envs

tests/v1/engine/test_engine_core.py

+# SPDX-License-Identifier: Apache-2.0
+
 import time
 import uuid
 

tests/v1/engine/test_engine_core_client.py

+# SPDX-License-Identifier: Apache-2.0
+
 import asyncio
 import time
 import uuid

tests/v1/engine/test_output_processor.py

+# SPDX-License-Identifier: Apache-2.0
+
 from typing import List
 
 import pytest

tests/v1/sample/test_sampler.py

+# SPDX-License-Identifier: Apache-2.0
+
 from typing import List, Set, Tuple
 
 import numpy as np

tests/v1/test_stats.py

+# SPDX-License-Identifier: Apache-2.0
+
 import pytest
 
 from vllm.sampling_params import SamplingParams

tests/v1/test_utils.py

+# SPDX-License-Identifier: Apache-2.0
+
 from typing import List
 
 import torch

tests/v1/worker/test_gpu_input_batch.py

+# SPDX-License-Identifier: Apache-2.0
+
 from typing import Dict, List, Set, Tuple
 
 import numpy as np

tests/vllm_test_utils/setup.py

+# SPDX-License-Identifier: Apache-2.0
+
 from setuptools import setup
 
 setup(

tests/vllm_test_utils/vllm_test_utils/__init__.py

+# SPDX-License-Identifier: Apache-2.0
 """
 vllm_utils is a package for vLLM testing utilities.
 It does not import any vLLM modules.

tests/vllm_test_utils/vllm_test_utils/blame.py

+# SPDX-License-Identifier: Apache-2.0
+
 import contextlib
 import dataclasses
 import sys

tests/vllm_test_utils/vllm_test_utils/monitor.py

+# SPDX-License-Identifier: Apache-2.0
+
 import contextlib
 import dataclasses
 import sys

tests/weight_loading/test_weight_loading.py

+# SPDX-License-Identifier: Apache-2.0
+
 import os
 
 import pytest