[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/worker/test_encoder_decoder_model_runner.py

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

tests/worker/test_model_input.py

+# SPDX-License-Identifier: Apache-2.0
+
 import dataclasses
 from typing import List, Tuple, Type
 

tests/worker/test_model_runner.py

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

tests/worker/test_profile.py

+# SPDX-License-Identifier: Apache-2.0
+
 import torch
 
 from vllm.engine.arg_utils import EngineArgs

tests/worker/test_swap.py

+# SPDX-License-Identifier: Apache-2.0
+
 import torch
 
 from vllm.engine.arg_utils import EngineArgs

tools/check_spdx_header.py

+# SPDX-License-Identifier: Apache-2.0
+
+import sys
+
+SPDX_HEADER = "# SPDX-License-Identifier: Apache-2.0"
+SPDX_HEADER_PREFIX = "# SPDX-License-Identifier:"
+
+
+def check_spdx_header(file_path):
+    with open(file_path, encoding='UTF-8') as file:
+        lines = file.readlines()
+        if not lines:
+            # not necessary for an empty file like __init__.py
+            return True
+        if not lines[0].strip().startswith(SPDX_HEADER_PREFIX):
+            return False
+    return True
+
+
+def add_header(file_path):
+    with open(file_path, 'r+', encoding='UTF-8') as file:
+        lines = file.readlines()
+        file.seek(0, 0)
+        file.write(SPDX_HEADER + '\n\n' + ''.join(lines))
+
+
+def main():
+    files_with_missing_header = []
+    for file_path in sys.argv[1:]:
+        if not check_spdx_header(file_path):
+            files_with_missing_header.append(file_path)
+
+    if files_with_missing_header:
+        print("The following files are missing the SPDX header:")
+        for file_path in files_with_missing_header:
+            print(f"  {file_path}")
+            add_header(file_path)
+
+    sys.exit(1 if files_with_missing_header else 0)
+
+
+if __name__ == "__main__":
+    main()

tools/profiler/print_layerwise_table.py

+# SPDX-License-Identifier: Apache-2.0
+
 import argparse
 import json
 from typing import Dict

tools/profiler/visualize_layerwise_profile.py

+# SPDX-License-Identifier: Apache-2.0
+
 import argparse
 import copy
 import json

tools/report_build_time_ninja.py

+# SPDX-License-Identifier: Apache-2.0
+
 #!/usr/bin/env python3
 # Copyright (c) 2018 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be

use_existing_torch.py

+# SPDX-License-Identifier: Apache-2.0
+
 import glob
 
 requires_files = glob.glob('requirements*.txt')

vllm/__init__.py

+# SPDX-License-Identifier: Apache-2.0
 """vLLM: a high-throughput and memory-efficient inference engine for LLMs"""
 import os
 

vllm/_custom_ops.py

+# SPDX-License-Identifier: Apache-2.0
+
 import contextlib
 import importlib
 from typing import TYPE_CHECKING, List, Optional, Tuple, Union

vllm/_ipex_ops.py

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

vllm/adapter_commons/layers.py

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

vllm/adapter_commons/models.py

+# SPDX-License-Identifier: Apache-2.0
+
 from abc import ABC, abstractmethod
 from typing import Any, Callable, Dict, Optional, TypeVar
 

vllm/adapter_commons/request.py

+# SPDX-License-Identifier: Apache-2.0
+
 from abc import ABC, abstractmethod
 
 

vllm/adapter_commons/utils.py

+# SPDX-License-Identifier: Apache-2.0
+
 from typing import Any, Callable, Dict, Optional, Set
 
 

vllm/adapter_commons/worker_manager.py

+# SPDX-License-Identifier: Apache-2.0
+
 from abc import ABC, abstractmethod
 from typing import Any, Optional, Set
 

vllm/assets/audio.py

+# SPDX-License-Identifier: Apache-2.0
+
 from dataclasses import dataclass
 from typing import Literal
 from urllib.parse import urljoin

vllm/assets/base.py

+# SPDX-License-Identifier: Apache-2.0
+
 from functools import lru_cache
 from pathlib import Path
 from typing import Optional