[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>

benchmarks/overheads/benchmark_hashing.py

+# SPDX-License-Identifier: Apache-2.0
+
 import cProfile
 import pstats
 

cmake/hipify.py

+# SPDX-License-Identifier: Apache-2.0
+
 #!/usr/bin/env python3
 
 #

collect_env.py

+# SPDX-License-Identifier: Apache-2.0
+
 # ruff: noqa
 # code borrowed from https://github.com/pytorch/pytorch/blob/main/torch/utils/collect_env.py
 

csrc/cutlass_extensions/vllm_cutlass_library_extension.py

+# SPDX-License-Identifier: Apache-2.0
+
 import enum
 from typing import Dict, Union
 

csrc/quantization/machete/generate.py

+# SPDX-License-Identifier: Apache-2.0
+
 import itertools
 import math
 import os

docs/source/conf.py

+# SPDX-License-Identifier: Apache-2.0
+
 # Configuration file for the Sphinx documentation builder.
 #
 # This file only contains a selection of the most common options. For a full

docs/source/generate_examples.py

+# SPDX-License-Identifier: Apache-2.0
+
 import itertools
 import re
 from dataclasses import dataclass, field

examples/offline_inference/aqlm_example.py

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

examples/offline_inference/arctic.py

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

examples/offline_inference/audio_language.py

+# SPDX-License-Identifier: Apache-2.0
 """
 This example shows how to use vLLM for running offline inference 
 with the correct prompt format on audio language models.

examples/offline_inference/basic.py

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

examples/offline_inference/basic_with_model_default_sampling.py

+# SPDX-License-Identifier: Apache-2.0
+
 from vllm import LLM
 
 # Sample prompts.

examples/offline_inference/chat.py

+# SPDX-License-Identifier: Apache-2.0
+
 from vllm import LLM, SamplingParams
 
 llm = LLM(model="meta-llama/Meta-Llama-3-8B-Instruct")

examples/offline_inference/chat_with_tools.py

+# SPDX-License-Identifier: Apache-2.0
+
 # ruff: noqa
 import json
 import random

examples/offline_inference/classification.py

+# SPDX-License-Identifier: Apache-2.0
+
 from vllm import LLM
 
 # Sample prompts.

examples/offline_inference/cli.py

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

examples/offline_inference/cpu_offload.py

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

examples/offline_inference/distributed.py

+# SPDX-License-Identifier: Apache-2.0
 """
 This example shows how to use Ray Data for running offline batch inference
 distributively on a multi-nodes cluster.

examples/offline_inference/embedding.py

+# SPDX-License-Identifier: Apache-2.0
+
 from vllm import LLM
 
 # Sample prompts.

examples/offline_inference/encoder_decoder.py

+# SPDX-License-Identifier: Apache-2.0
 '''
 Demonstrate prompting of text-to-text
 encoder/decoder models, specifically BART