[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/test_regression.py

+# SPDX-License-Identifier: Apache-2.0
 """Containing tests that check for regressions in vLLM's behavior.
 
 It should include tests that are reported by users and making sure they

tests/test_sampling_params.py

+# SPDX-License-Identifier: Apache-2.0
 """Tests for the SamplingParams class.
 """
 from vllm import SamplingParams

tests/test_scalartype.py

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

tests/test_sequence.py

+# SPDX-License-Identifier: Apache-2.0
+
 import pytest
 
 from vllm.model_executor.layers.sampler import SamplerOutput

tests/test_sharded_state_loader.py

+# SPDX-License-Identifier: Apache-2.0
+
 import multiprocessing as mp
 import os
 import shutil

tests/test_utils.py

+# SPDX-License-Identifier: Apache-2.0
+
 import asyncio
 import os
 import socket

tests/tokenization/test_cached_tokenizer.py

+# SPDX-License-Identifier: Apache-2.0
+
 from copy import deepcopy
 
 from transformers import AutoTokenizer

tests/tokenization/test_detokenize.py

+# SPDX-License-Identifier: Apache-2.0
+
 from typing import Any, Dict, Generator, List, Optional
 
 import pytest

tests/tokenization/test_get_eos.py

+# SPDX-License-Identifier: Apache-2.0
 """
 This test file includes some cases where it is inappropriate to
 only get the `eos_token_id` from the tokenizer as defined by

tests/tokenization/test_tokenizer.py

+# SPDX-License-Identifier: Apache-2.0
+
 import pytest
 from transformers import PreTrainedTokenizerBase
 

tests/tokenization/test_tokenizer_group.py

+# SPDX-License-Identifier: Apache-2.0
+
 import asyncio
 import os
 import sys

tests/tool_use/conftest.py

+# SPDX-License-Identifier: Apache-2.0
+
 import pytest
 import pytest_asyncio
 from huggingface_hub import snapshot_download

tests/tool_use/test_chat_completion_request_validations.py

+# SPDX-License-Identifier: Apache-2.0
+
 import pytest
 
 from vllm.entrypoints.openai.protocol import ChatCompletionRequest

tests/tool_use/test_chat_completions.py

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

tests/tool_use/test_jamba_tool_parser.py

+# SPDX-License-Identifier: Apache-2.0
+
 import json
 from typing import Generator, List, Optional
 

tests/tool_use/test_parallel_tool_calls.py

+# SPDX-License-Identifier: Apache-2.0
+
 import json
 from typing import Dict, List, Optional
 

tests/tool_use/test_tool_calls.py

+# SPDX-License-Identifier: Apache-2.0
+
 import json
 from typing import Dict, List, Optional
 

tests/tool_use/utils.py

+# SPDX-License-Identifier: Apache-2.0
+
 from copy import deepcopy
 from typing import Any, Dict, List, Optional
 

tests/tpu/test_compilation.py

+# SPDX-License-Identifier: Apache-2.0
+
 import glob
 import os
 import tempfile

tests/tpu/test_custom_dispatcher.py

+# SPDX-License-Identifier: Apache-2.0
+
 import os
 
 from vllm.config import CompilationLevel