Cuda 13 support

[johnnynunez]

# --- PATCH: replace deprecated cub::Equality with a portable functor ---
# 1) Ensure we can include thrust functors if needed.
grep -q '#include <thrust/functional.h>' nerfacc/cuda/csrc/scan_cub.cu || \
  sed -i '1i #include <thrust/functional.h>' nerfacc/cuda/csrc/scan_cub.cu

# 2) Define a tiny comparator that works across CUB versions.
#    (Templated operator() so it matches whatever KeyT is.)
awk '
/^#include/ {print; next}
!p && /^[[:space:]]*$/ {print; next}
!p {
  print "";
  print "struct EqualByKey {";
  print "  template <typename T>";
  print "  __host__ __device__ bool operator()(const T& a, const T& b) const { return a == b; }";
  print "};";
  print "";
  p=1
}
{print}
' nerfacc/cuda/csrc/scan_cub.cu > nerfacc/cuda/csrc/scan_cub.cu.new && mv nerfacc/cuda/csrc/scan_cub.cu.new nerfacc/cuda/csrc/scan_cub.cu

# 3) Swap all uses of cub::Equality() to our functor.
sed -i 's/cub::Equality()/EqualByKey()/g' nerfacc/cuda/csrc/scan_cub.cu

# (Alternative you could use: sed -i "s/cub::Equality()/thrust::equal_to<int32_t>()/g" ...)

# 4) Fix the trailing-backslash warning by ensuring a newline at EOF.
#    This removes a stray final backslash and ensures newline exists.
#    If no backslash issue, this is harmless.
sed -i -e '$a\' nerfacc/cuda/csrc/include/utils.cub.cuh