[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/attention/ops/blocksparse_attention/interface.py

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

vllm/attention/ops/blocksparse_attention/utils.py

+# SPDX-License-Identifier: Apache-2.0
+
 # Helper functions for 3D sparse pattern
 # These function are not optimized and very inefficient.
 # Avoid calling them too frequent or use a cache mechanism.

vllm/attention/ops/hpu_paged_attn.py

+# SPDX-License-Identifier: Apache-2.0
+
 ###############################################################################
 # Copyright (C) 2024 Habana Labs, Ltd. an Intel Company
 ###############################################################################

vllm/attention/ops/ipex_attn.py

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

vllm/attention/ops/nki_flash_attn.py

+# SPDX-License-Identifier: Apache-2.0
+
 from dataclasses import dataclass
 
 import neuronxcc.nki.isa as nisa

vllm/attention/ops/paged_attn.py

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

vllm/attention/ops/prefix_prefill.py

+# SPDX-License-Identifier: Apache-2.0
+
 # The kernels in this file are adapted from LightLLM's context_attention_fwd:
 # https://github.com/ModelTC/lightllm/blob/main/lightllm/models/llama/triton_kernel/context_flashattention_nopad.py
 

vllm/attention/ops/triton_decode_attention.py

+# SPDX-License-Identifier: Apache-2.0
+
 # Adapted from
 # https://github.com/sgl-project/sglang/blob/9f635ea50de920aa507f486daafba26a5b837574/python/sglang/srt/layers/attention/triton_ops/decode_attention.py
 # which was originally adapted from

vllm/attention/ops/triton_flash_attention.py

+# SPDX-License-Identifier: Apache-2.0
+
 #!/usr/bin/env python
 """
 Fused Attention

vllm/attention/selector.py

+# SPDX-License-Identifier: Apache-2.0
+
 import os
 from contextlib import contextmanager
 from functools import cache

vllm/beam_search.py

+# SPDX-License-Identifier: Apache-2.0
+
 from dataclasses import dataclass
 from typing import TYPE_CHECKING, Any, Dict, List, Optional, Union
 

vllm/compilation/backends.py

+# SPDX-License-Identifier: Apache-2.0
+
 import ast
 import copy
 import dataclasses

vllm/compilation/counter.py

+# SPDX-License-Identifier: Apache-2.0
+
 import copy
 import dataclasses
 from contextlib import contextmanager

vllm/compilation/decorators.py

+# SPDX-License-Identifier: Apache-2.0
+
 import inspect
 from typing import Callable, Dict, List, Optional, TypeVar, Union, overload
 from unittest.mock import patch

vllm/compilation/fix_functionalization.py

+# SPDX-License-Identifier: Apache-2.0
+
 import operator
 from typing import Dict, Iterable, List, Optional, Tuple, Union
 

vllm/compilation/fusion.py

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

vllm/compilation/fx_utils.py

+# SPDX-License-Identifier: Apache-2.0
+
 import operator
 from typing import Iterable, Optional
 

vllm/compilation/inductor_pass.py

+# SPDX-License-Identifier: Apache-2.0
+
 import hashlib
 import inspect
 import types

vllm/compilation/monitor.py

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

vllm/compilation/multi_output_match.py

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