Make pinned package versions in setup.py less restrictive

[Fish-Soup]

Hi

Currently lightGBMLSS fixes many packages in the stetup.py. This can make it difficult to use in production as the package requires specific versions of sub-packages, some of which might conflict with other dependencies in the project.

Could we loosen the version requirements a bit
e.g.
optuna>=3.1.0, <4.0.0