[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 ...

vllm/model_executor/layers/quantization/base_config.py

+# SPDX-License-Identifier: Apache-2.0
+
 import inspect
 from abc import ABC, abstractmethod
 from typing import Any, Dict, List, Optional, Type

vllm/model_executor/layers/quantization/bitsandbytes.py

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

vllm/model_executor/layers/quantization/compressed_tensors/compressed_tensors.py

+# SPDX-License-Identifier: Apache-2.0
+
 from contextlib import suppress
 from typing import Any, Dict, List, Literal, Optional, Tuple, cast
 

vllm/model_executor/layers/quantization/compressed_tensors/compressed_tensors_moe.py

+# SPDX-License-Identifier: Apache-2.0
+
 import enum
 from enum import Enum
 from typing import Callable, List, Optional

vllm/model_executor/layers/quantization/compressed_tensors/schemes/__init__.py

+# SPDX-License-Identifier: Apache-2.0
+
 from .compressed_tensors_scheme import CompressedTensorsScheme
 from .compressed_tensors_w4a16_24 import (W4A16SPARSE24_SUPPORTED_BITS,
                                           CompressedTensorsW4A16Sparse24)

vllm/model_executor/layers/quantization/compressed_tensors/schemes/compressed_tensors_24.py

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

vllm/model_executor/layers/quantization/compressed_tensors/schemes/compressed_tensors_scheme.py

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

vllm/model_executor/layers/quantization/compressed_tensors/schemes/compressed_tensors_w4a16_24.py

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

vllm/model_executor/layers/quantization/compressed_tensors/schemes/compressed_tensors_w8a16_fp8.py

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

vllm/model_executor/layers/quantization/compressed_tensors/schemes/compressed_tensors_w8a8_fp8.py

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

vllm/model_executor/layers/quantization/compressed_tensors/schemes/compressed_tensors_w8a8_int8.py

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

vllm/model_executor/layers/quantization/compressed_tensors/schemes/compressed_tensors_wNa16.py

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

vllm/model_executor/layers/quantization/compressed_tensors/triton_scaled_mm.py

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

vllm/model_executor/layers/quantization/compressed_tensors/utils.py

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

vllm/model_executor/layers/quantization/deepspeedfp.py

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

vllm/model_executor/layers/quantization/experts_int8.py

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

vllm/model_executor/layers/quantization/fbgemm_fp8.py

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

vllm/model_executor/layers/quantization/fp8.py

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

vllm/model_executor/layers/quantization/gguf.py

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

vllm/model_executor/layers/quantization/gptq.py

+# SPDX-License-Identifier: Apache-2.0
+
 import enum
 from enum import Enum
 from fractions import Fraction