Fixes broken export LD_LIBRARY_PATH cmd in README.md

[gregtzar]

The current cmd to export the LD_LIBRARY_PATH gave the following error on my machine:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "<frozen posixpath>", line 181, in dirname
TypeError: expected str, bytes or os.PathLike object, not NoneType

This has been reported in issue: #1320 and this update fixes the error.

Reason: In recent versions of nvidia-cublas-cu12 and nvidia-cudnn-cu12, NVIDIA changed how these packages are structured. The submodules are namespaces or do not explicitly declare a file property anymore, returning None across the board.

[MahmoudAshraf97]

Hi and thanks for the contribution, however, the correct place to fix this is in CTranslate 2, it should be able to accept the pypi packages without having to point it explicitly, then we can remove the wrong export completely

[gregtzar]

@MahmoudAshraf97 I see, that would certainly be ideal. Hopefully in the meantime though we could at least fix the import paths that are currently required so it doesn't confuse anyone else.