Add compatibility for numpy 2 while preserving numpy 1 compatibility

[neilmehta24]

Check the numpy major version number before deciding which file to import methods from.

I have not benchmarked numpy 1 vs numpy 2 performance for outlines, but I have verified that outlines works as intended when using numpy 2 for the examples in the README.

Closes #1104

[ur4t]

@rlouf Could you please review and merge this PR? Torch has moved to Numpy 2.0 for quite a long time and there might be potential breakages to downgrade Numpy.

[rlouf]

Sure, will merge if CI is green.

[neilmehta24]

=========================== short test summary info ============================
ERROR tests/generate/test_integration_transformers_vision.py::test_single_image_text_gen - OSError: trl-internal-testing/tiny-random-LlavaForConditionalGeneration is not a local folder and is not a valid model identifier listed on 'https://huggingface.co/models'
If this is a private repository, make sure to pass a token having permission to this repo either by logging in with `huggingface-cli login` or by passing `token=<your_token>`
ERROR tests/generate/test_integration_transformers_vision.py::test_multi_image_text_gen - OSError: trl-internal-testing/tiny-random-LlavaForConditionalGeneration is not a local folder and is not a valid model identifier listed on 'https://huggingface.co/models'
If this is a private repository, make sure to pass a token having permission to this repo either by logging in with `huggingface-cli login` or by passing `token=<your_token>`
ERROR tests/generate/test_integration_transformers_vision.py::test_mismatched_image_text_gen - OSError: trl-internal-testing/tiny-random-LlavaForConditionalGeneration is not a local folder and is not a valid model identifier listed on 'https://huggingface.co/models'
If this is a private repository, make sure to pass a token having permission to this repo either by logging in with `huggingface-cli login` or by passing `token=<your_token>`
ERROR tests/generate/test_integration_transformers_vision.py::test_single_image_choice - OSError: trl-internal-testing/tiny-random-LlavaForConditionalGeneration is not a local folder and is not a valid model identifier listed on 'https://huggingface.co/models'
If this is a private repository, make sure to pass a token having permission to this repo either by logging in with `huggingface-cli login` or by passing `token=<your_token>`
= 478 passed, 232 skipped, 1 xfailed, 2 xpassed, 4 errors in 720.44s (0:12:00) =

🤔
Will dig deeper into this failure later this week. On the face of it, doesn't seem related to the numpy change

[rlouf]

It's completely unrelated so I'll go ahead and merge. Thank you for the contribution!