GPU RNTuple reading doesn't work with new versions of kvikio

[ariostas]

The kvikio.nvcomp_codec module was deprecated and removed a while ago, so now RNTuple reading on GPU doesn't work.

@fstrug Do you know if we can just switch to adding the nvidia-nvcomp-cu12 dependency and make the following substitutions? Or are there some subtleties?

import kvikio.nvcomp_codec as kvikio_nvcomp_codec -> from nvidia import nvcomp
kvikio_nvcomp_codec.NvCompBatchCodec -> nvcomp.Codec
codec.decode_batch -> codec.decode

[fstrug]

Hi @ariostas, I think that is essentially the bulk of the changes. Additionally as far as I can tell, the nvcomp library does not work with cupy.ndarray and instead has it's own array object which can be converted to using nvcomp.as_array(). There is an additional step of casting the cupy objects to nvcomp objects and then back again for decompression.