[Misc] Add SPDX-FileCopyrightText (#19100)

Signed-off-by: simon-mo <simon.mo@hey.com>

tests/kernels/moe/test_cutlass_moe.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 import dataclasses
 from typing import Optional
 

tests/kernels/moe/test_moe.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 """Tests for the MOE layers.
 
 Run `pytest tests/kernels/test_moe.py`.

tests/kernels/moe/test_moe_permute_unpermute.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 """Tests for the MOE permute/unpermute kernel
 
 Run `pytest tests/kernels/test_moe_permute_unpermute.py`.

tests/kernels/moe/test_nvfp4_moe.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 import pytest
 import torch
 

tests/kernels/moe/test_pplx_moe.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 """Tests for the MOE layers.
 
 Run `pytest tests/kernels/test_pplx_moe.py`.

tests/kernels/moe/test_rocm_aiter_topk.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 # This is a test for the AITER ops.
 # It tests if the AITER ops are
 # 1. correctly registered as custom ops

tests/kernels/moe/test_triton_moe_ptpc_fp8.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 # Adapted from https://github.com/sgl-project/sglang/blob/main/test/srt/test_triton_moe_channel_fp8_kernel.py
 import itertools

tests/kernels/quant_utils.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 from typing import Optional, Union
 

tests/kernels/quantization/nvfp4_utils.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 import torch
 
 from vllm.scalar_type import scalar_types

tests/kernels/quantization/test_allspark_gemm.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 import pytest
 import torch
 

tests/kernels/quantization/test_aqlm.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 import torch
 

tests/kernels/quantization/test_awq.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 import pytest
 import torch

tests/kernels/quantization/test_awq_triton.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 """Tests for the AWQ Triton kernel.
 
 Run `pytest tests/kernels/test_awq_triton.py`.

tests/kernels/quantization/test_block_fp8.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 # Adapted from https://github.com/sgl-project/sglang/pull/2575
 import itertools

tests/kernels/quantization/test_block_int8.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 # Adapted from https://github.com/sgl-project/sglang/blob/main/test/srt/test_block_int8.py
 import itertools

tests/kernels/quantization/test_cutlass_2of4_sparse.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 """Tests for sparse cutlass kernels
 
 Run `pytest tests/kernels/test_semi_structured.py`.

tests/kernels/quantization/test_cutlass_scaled_mm.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 """Tests for cutlass kernels
 
 Run `pytest tests/kernels/test_cutlass.py`.

tests/kernels/quantization/test_fp8_quant.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 import pytest
 import torch

tests/kernels/quantization/test_ggml.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 import gguf
 import pytest

tests/kernels/quantization/test_gguf.py

 # SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 from pathlib import Path