add cloudpickle to requirements-dev.txt

[SajjadPSavoji]

had to install cloudpickle manually when installing with python3.8 under Conda virtual env.

PR Type (Fix)

Short Description

Installed kscope via PyPI in cluster with python=3.8 under a Conda virtual env.
Upon import scope I got Module Not Found error for cloudpickle.

It seems like this lib should be added under requirements.txt

[SajjadPSavoji]

alright the unit and integration testing is not passing, due to the same error.

    import cloudpickle
E   ModuleNotFoundError: No module named 'cloudpickle'
=========================== short test summary info ============================
ERROR test/integration_tests/test_system.py
ERROR test/unit_tests/test_batch_prompting.py
ERROR test/unit_tests/test_package_import.py
ERROR test/unit_tests/test_sdk_functions.py
!!!!!!!!!!!!!!!!!!! Interrupted: 4 errors during collection !!!!!!!!!!!!!!!!!!!!
============================== 4 errors in 1.78s ===============================
Error: Process completed with exit code 2.

Not sure how to add this requirement to package, maybe in setup.py:line19

    install_requires=[
        "certifi==2022.12.7",
        "charset-normalizer==3.0.1",
        "idna==3.4",
        "requests==2.28.2",
        "torch==1.13.1",
        "typing_extensions==4.4.0",
        "urllib3==1.26.14",
        "numpy",
    ],