Use SPDX for all copyright headers

[KyleFromNVIDIA]

Issue: https://github.com/rapidsai/build-infra/issues/297

[robertmaynard]

Files needing changes:

.flake8
conda/recipes/cuvs/recipe.yaml
conda/recipes/libcuvs/recipe.yaml
conda/recipes/cuvs-bench/recipe.yaml
conda/recipes/cuvs-bench-cpu/recipe.yaml
cpp/src/neighbors/detail/faiss_distance_utils.h
.pre-commit-config.yaml

[robertmaynard]

Files that need dual AND SPD markup

cpp/src/distance/detail/fused_distance_nn/gemm.h
cpp/src/distance/detail/fused_distance_nn/epilogue.cuh
cpp/src/distance/detail/fused_distance_nn/predicated_tile_iterator_normvec_smem.h
cpp/src/distance/detail/fused_distance_nn/persistent_gemm.h
cpp/src/distance/detail/fused_distance_nn/epilogue_elementwise.cuh
cpp/src/distance/detail/fused_distance_nn/predicated_tile_iterator_reduced_vec.h
cpp/src/distance/detail/fused_distance_nn/custom_epilogue_with_broadcast.h

[KyleFromNVIDIA]

Looking at cpp/src/distance/detail/fused_distance_nn/gemm.h, it looks like we own it, and the BSD-3-Clause is left over from the 2017-2023 era. It looks like we simply relicensed this file. I don't see any other ownership. I think we can leave it as Apache-2.0. I'll confirm the others, but I suspect they have the same deal.

[robertmaynard]

Looking at cpp/src/distance/detail/fused_distance_nn/gemm.h, it looks like we own it, and the BSD-3-Clause is left over from the 2017-2023 era.

I don't know if we need permission from the cutlass team as that is the original source

[robertmaynard]

cpp/cmake/modules/FindAVX.cmake Missing 7 copyright authors

[robertmaynard]

cpp/src/neighbors/detail/faiss_distance_utils.h is missing SPDX-FileCopyrightText: Copyright (c) Facebook, Inc.

[benfred]

/merge