[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>

vllm/platforms/xpu.py

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

vllm/plugins/__init__.py

+# SPDX-License-Identifier: Apache-2.0
+
 import logging
 import os
 from typing import Callable, Dict

vllm/pooling_params.py

+# SPDX-License-Identifier: Apache-2.0
+
 from typing import Any, Optional
 
 import msgspec

vllm/profiler/__init__.py

+# SPDX-License-Identifier: Apache-2.0
+
 from .layerwise_profile import layerwise_profile
 
 __all__ = [

vllm/profiler/layerwise_profile.py

+# SPDX-License-Identifier: Apache-2.0
+
 import copy
 from collections import defaultdict
 from dataclasses import asdict, dataclass, field

vllm/profiler/utils.py

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

vllm/prompt_adapter/layers.py

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

vllm/prompt_adapter/models.py

+# SPDX-License-Identifier: Apache-2.0
+
 import logging
 import math
 from typing import Any, Callable, Dict, List, Optional, Type

vllm/prompt_adapter/request.py

+# SPDX-License-Identifier: Apache-2.0
+
 import msgspec
 
 from vllm.adapter_commons.request import AdapterRequest

vllm/prompt_adapter/utils.py

+# SPDX-License-Identifier: Apache-2.0
+
 # code borrowed from: https://github.com/huggingface/peft/blob/v0.12.0/src/peft/utils/save_and_load.py#L420
 
 import os

vllm/prompt_adapter/worker_manager.py

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

vllm/sampling_params.py

+# SPDX-License-Identifier: Apache-2.0
 """Sampling parameters for text generation."""
 import copy
 from dataclasses import dataclass

vllm/scalar_type.py

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

vllm/scripts.py

+# SPDX-License-Identifier: Apache-2.0
+
 # The CLI entrypoint to vLLM.
 import argparse
 import os

vllm/sequence.py

+# SPDX-License-Identifier: Apache-2.0
 """Sequence and its related classes."""
 import copy
 import enum

vllm/spec_decode/batch_expansion.py

+# SPDX-License-Identifier: Apache-2.0
+
 from array import array
 from itertools import chain, count
 from typing import Iterator, List, Optional, Tuple

vllm/spec_decode/draft_model_runner.py

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

vllm/spec_decode/interfaces.py

+# SPDX-License-Identifier: Apache-2.0
+
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
 from typing import List, Optional, Set, Union

vllm/spec_decode/medusa_worker.py

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

vllm/spec_decode/metrics.py

+# SPDX-License-Identifier: Apache-2.0
+
 import time
 from typing import Callable, Optional, Union